xorg screen found but no valid modes 7.04 to 7.10 PPC/Radeon

here's my xorg.conf

# xorg.conf (xorg X Window System server configuration file)
#
# This file was generated by dexconf, the Debian X Configuration tool, using
# values from the debconf database.
#
# Edit this file with caution, and see the xorg.conf manual page.
# (Type "man xorg.conf" at the shell prompt.)
#
# This file is automatically updated on xserver-xorg package upgrades *only*
# if it has not been modified since the last upgrade of the xserver-xorg
# package.
#
# If you have edited this file but would like it to be automatically updated
# again, run the following command:
# sudo dpkg-reconfigure -phigh xserver-xorg

Section "Files"
EndSection

Section "InputDevice"
 Identifier "Generic Keyboard"
 Driver "kbd"
 Option "CoreKeyboard"
 Option "XkbRules" "xorg"
 Option "XkbModel" "pc104"
 Option "XkbLayout" "us"
EndSection

Section "InputDevice"
 Identifier "Configured Mouse"
 Driver "mouse"
 Option "CorePointer"
 Option "Device" "/dev/input/mice"
 Option "Protocol" "ImPS/2"
 Option "ZAxisMapping" "4 5"
EndSection

Section "InputDevice"
 Driver "wacom"
 Identifier "stylus"
 Option "Device" "/dev/input/wacom"
 Option "Type" "stylus"
 Option "ForceDevice" "ISDV4" # Tablet PC ONLY
EndSection

Section "InputDevice"
 Driver "wacom"
 Identifier "eraser"
 Option "Device" "/dev/input/wacom"
 Option "Type" "eraser"
 Option "ForceDevice" "ISDV4" # Tablet PC ONLY
EndSection

Section "InputDevice"
 Driver "wacom"
 Identifier "cursor"
 Option "Device" "/dev/input/wacom"
 Option "Type" "cursor"
 Option "ForceDevice" "ISDV4" # Tablet PC ONLY
EndSection

Section "Device"
 Identifier "ATI Technologies Inc RV280 [Radeon 9200]"
 Driver "ati"
 BusID "PCI:0:16:0"
 Option "UseFBDev" "true"
EndSection

Section "Monitor"
 Identifier "SyncMaster"
 Option "DPMS"
 HorizSync 30-100
 VertRefresh 50-160
EndSection

Section "Screen"
 Identifier "Default Screen"
 Device "ATI Technologies Inc RV280 [Radeon 9200]"
 Monitor "SyncMaster"
 DefaultDepth 24
 SubSection "Display"
  Modes "1280x1024" "1024x768" "800x600" "640x480"
 EndSubSection
EndSection

Section "ServerLayout"
 Identifier "Default Layout"
 Screen "Default Screen"
 InputDevice "Generic Keyboard"
 InputDevice "Configured Mouse"

# Uncomment if you have a wacom tablet
# InputDevice "stylus" "SendCoreEvents"
# InputDevice "cursor" "SendCoreEvents"
# InputDevice "eraser" "SendCoreEvents"
EndSection

Heres my Xorg.0.log

X Window System Version 1.3.0
Release Date: 19 April 2007
X Protocol Version 11, Revision 0, Release 1.3
Build Operating System: Linux Ubuntu (xorg-server 2:1.3.0.0.dfsg-12ubuntu8)
Current Operating System: Linux zim 2.6.15-26-powerpc #1 Fri Sep 8 19:51:33 UTC 2006 ppc
Build Date: 29 September 2007
 Before reporting problems, check http://wiki.x.org
 to make sure that you have the latest version.
Module Loader present
Markers: (--) probed, (**) from config file, (==) default setting,
 (++) from command line, (!!) notice, (II) informational,
 (WW) warning, (EE) error, (NI) not implemented, (??) unknown.
(==) Log file: "/var/log/Xorg.0.log", Time: Thu Dec 20 05:17:03 2007
(==) Using config file: "/etc/X11/xorg.conf"
(==) ServerLayout "Default Layout"
(**) |-->Screen "Default Screen" (0)
(**) | |-->Monitor "SyncMaster"
(**) | |-->Device "ATI Technologies Inc RV280 [Radeon 9200]"
(**) |-->Input Device "Generic Keyboard"
(**) |-->Input Device "Configured Mouse"
(WW) The directory "/usr/share/fonts/X11/cyrillic" does not exist.
 Entry deleted from font path.
(==) FontPath set to:
 /usr/share/fonts/X11/misc,
 /usr/share/fonts/X11/100dpi/:unscaled,
 /usr/share/fonts/X11/75dpi/:unscaled,
 /usr/share/fonts/X11/Type1,
 /usr/share/fonts/X11/100dpi,
 /usr/share/fonts/X11/75dpi,
 /var/lib/defoma/x-ttcidfont-conf.d/dirs/TrueType
(==) RgbPath set to "/etc/X11/rgb"
(==) ModulePath set to "/usr/lib/xorg/modules"
(II) Open APM successful
(II) Loader magic: 0x101fb2e8
(II) Module ABI versions:
 X.Org ANSI C Emulation: 0.3
 X.Org Video Driver: 1.2
 X.Org XInput driver : 0.7
 X.Org Server Extension : 0.3
 X.Org Font Renderer : 0.5
(II) Loader running on linux
(II) LoadModule: "pcidata"
(II) Loading /usr/lib/xorg/modules//libpcidata.so
(II) Module pcidata: vendor="X.Org Foundation"
 compiled for 1.3.0, module version = 1.0.0
 ABI class: X.Org Video Driver, version 1.2
(--) using VT number 10

(II) PCI: PCI scan (all values are in hex)
(II) PCI: 00:0b:0: chip 106b,0034 card 0000,0000 rev 00 class 06,00,00 hdr 00
(II) PCI: 00:10:0: chip 1002,5962 card 1002,5962 rev 01 class 03,00,00 hdr 00
(II) PCI: 10:0b:0: chip 106b,0035 card 0000,0000 rev 00 class 06,00,00 hdr 00
(II) PCI: 10:17:0: chip 106b,003e card 0000,0000 rev 00 class ff,00,00 hdr 00
(II) PCI: 10:18:0: chip 106b,003f card 0000,0000 rev 00 class 0c,03,10 hdr 00
(II) PCI: 10:19:0: chip 106b,003f card 0000,0000 rev 00 class 0c,03,10 hdr 00
(II) PCI: 10:1a:0: chip 106b,003f card 0000,0000 rev 00 class 0c,03,10 hdr 00
(II) PCI: 10:1b:0: chip 1033,0035 card 1033,0035 rev 43 class 0c,03,10 hdr 80
(II) PCI: 10:1b:1: chip 1033,0035 card 1033,0035 rev 43 class 0c,03,10 hdr 00
(II) PCI: 10:1b:2: chip 1033,00e0 card 1033,00e0 rev 04 class 0c,03,20 hdr 00
(II) PCI: 20:0b:0: chip 106b,0036 card 0000,0000 rev 00 class 06,00,00 hdr 00
(II) PCI: 20:0d:0: chip 106b,003b card 0000,0000 rev 00 class ff,00,00 hdr 00
(II) PCI: 20:0e:0: chip 106b,0031 card 106b,5811 rev 81 class 0c,00,10 hdr 00
(II) PCI: 20:0f:0: chip 106b,0032 card 0000,0000 rev 80 class 02,00,00 hdr 00
(II) PCI: End of PCI scan
(II) Host-to-PCI bridge:
(II) Bus 0: bridge is at (0:11:0), (0,0,32), BCTRL: 0x0008 (VGA_EN is set)
(II) Bus 0 I/O range:
 [0] -1 0 0x00000000 - 0x0000ffff (0x10000) IX[B]
(II) Bus 0 non-prefetchable memory range:
 [0] -1 0 0x00000000 - 0xffffffff (0x0) MX[B]
(II) Bus 0 prefetchable memory range:
 [0] -1 0 0x00000000 - 0xffffffff (0x0) MX[B]
(II) Host-to-PCI bridge:
(II) Bus 16: bridge is at (16:11:0), (16,16,32), BCTRL: 0x0008 (VGA_EN is set)
(II) Bus 16 I/O range:
 [0] -1 0 0x00000000 - 0x0000ffff (0x10000) IX[B]
(II) Bus 16 non-prefetchable memory range:
 [0] -1 0 0x00000000 - 0xffffffff (0x0) MX[B]
(II) Bus 16 prefetchable memory range:
 [0] -1 0 0x00000000 - 0xffffffff (0x0) MX[B]
(II) Host-to-PCI bridge:
(II) Bus 32: bridge is at (32:11:0), (32,32,32), BCTRL: 0x0008 (VGA_EN is set)
(II) Bus 32 I/O range:
 [0] -1 0 0x00000000 - 0x0000ffff (0x10000) IX[B]
(II) Bus 32 non-prefetchable memory range:
 [0] -1 0 0x00000000 - 0xffffffff (0x0) MX[B]
(II) Bus 32 prefetchable memory range:
 [0] -1 0 0x00000000 - 0xffffffff (0x0) MX[B]
(--) PCI:*(0:16:0) ATI Technologies Inc RV280 [Radeon 9200] rev 1, Mem @ 0x98000000/27, 0x90000000/16, I/O @ 0x0400/8, BIOS @ 0xf1000000/17
(II) Addressable bus resource ranges are
 [0] -1 0 0x00000000 - 0xffffffff (0x0) MX[B]
 [1] -1 0 0x00000000 - 0x0000ffff (0x10000) IX[B]
(II) OS-reported resource ranges:
 [0] -1 0 0x00100000 - 0x3fffffff (0x3ff00000) MX[B]E(B)
 [1] -1 0 0x000f0000 - 0x000fffff (0x10000) MX[B]
 [2] -1 0 0x000c0000 - 0x000effff (0x30000) MX[B]
 [3] -1 0 0x00000000 - 0x0009ffff (0xa0000) MX[B]
 [4] -1 0 0x0000ffff - 0x0000ffff (0x1) IX[B]
 [5] -1 0 0x00000000 - 0x000000ff (0x100) IX[B]
(II) Active PCI resource ranges:
 [0] -1 0 0xf5200000 - 0xf53fffff (0x200000) MX[B]E
 [1] -1 0 0xf5000000 - 0xf5ffffff (0x1000000) MX[B]E
 [2] -1 0 0xf5004000 - 0xf5007fff (0x4000) MX[B]E
 [3] -1 0 0x80080000 - 0x800fffff (0x80000) MX[B]E
 [4] -1 0 0x80081000 - 0x80081fff (0x1000) MX[B]E
 [5] -1 0 0x80082000 - 0x80083fff (0x2000) MX[B]E
 [6] -1 0 0x80083000 - 0x80083fff (0x1000) MX[B]E
 [7] -1 0 0x80000000 - 0xffffffff (0x80000000) MX[B]E
 [8] -1 0 0xf1000000 - 0xf101ffff (0x20000) MX[B](B)
 [9] -1 0 0x90000000 - 0x9000ffff (0x10000) MX[B](B)
 [10] -1 0 0x98000000 - 0x9fffffff (0x8000000) MX[B](B)
 [11] -1 0 0xf0000400 - 0xf00004ff (0x100) IX[B](B)
(II) PCI Memory resource overlap reduced 0xf5000000 from 0xf5ffffff to 0xf5003fff
(II) PCI Memory resource overlap reduced 0x80080000 from 0x800fffff to 0x80080fff
(II) PCI Memory resource overlap reduced 0x80082000 from 0x80083fff to 0x80082fff
(II) PCI Memory resource overlap reduced 0x80000000 from 0xffffffff to 0x8007ffff
(II) Active PCI resource ranges after removing overlaps:
 [0] -1 0 0xf5200000 - 0xf53fffff (0x200000) MX[B]E
 [1] -1 0 0xf5000000 - 0xf5003fff (0x4000) MX[B]E
 [2] -1 0 0xf5004000 - 0xf5007fff (0x4000) MX[B]E
 [3] -1 0 0x80080000 - 0x80080fff (0x1000) MX[B]E
 [4] -1 0 0x80081000 - 0x80081fff (0x1000) MX[B]E
 [5] -1 0 0x80082000 - 0x80082fff (0x1000) MX[B]E
 [6] -1 0 0x80083000 - 0x80083fff (0x1000) MX[B]E
 [7] -1 0 0x80000000 - 0x8007ffff (0x80000) MX[B]E
 [8] -1 0 0xf1000000 - 0xf101ffff (0x20000) MX[B](B)
 [9] -1 0 0x90000000 - 0x9000ffff (0x10000) MX[B](B)
 [10] -1 0 0x98000000 - 0x9fffffff (0x8000000) MX[B](B)
 [11] -1 0 0xf0000400 - 0xf00004ff (0x100) IX[B](B)
(II) OS-reported resource ranges after removing overlaps with PCI:
 [0] -1 0 0x00100000 - 0x3fffffff (0x3ff00000) MX[B]E(B)
 [1] -1 0 0x000f0000 - 0x000fffff (0x10000) MX[B]
 [2] -1 0 0x000c0000 - 0x000effff (0x30000) MX[B]
 [3] -1 0 0x00000000 - 0x0009ffff (0xa0000) MX[B]
 [4] -1 0 0x0000ffff - 0x0000ffff (0x1) IX[B]
 [5] -1 0 0x00000000 - 0x000000ff (0x100) IX[B]
(II) All system resource ranges:
 [0] -1 0 0x00100000 - 0x3fffffff (0x3ff00000) MX[B]E(B)
 [1] -1 0 0x000f0000 - 0x000fffff (0x10000) MX[B]
 [2] -1 0 0x000c0000 - 0x000effff (0x30000) MX[B]
 [3] -1 0 0x00000000 - 0x0009ffff (0xa0000) MX[B]
 [4] -1 0 0xf5200000 - 0xf53fffff (0x200000) MX[B]E
 [5] -1 0 0xf5000000 - 0xf5003fff (0x4000) MX[B]E
 [6] -1 0 0xf5004000 - 0xf5007fff (0x4000) MX[B]E
 [7] -1 0 0x80080000 - 0x80080fff (0x1000) MX[B]E
 [8] -1 0 0x80081000 - 0x80081fff (0x1000) MX[B]E
 [9] -1 0 0x80082000 - 0x80082fff (0x1000) MX[B]E
 [10] -1 0 0x80083000 - 0x80083fff (0x1000) MX[B]E
 [11] -1 0 0x80000000 - 0x8007ffff (0x80000) MX[B]E
 [12] -1 0 0xf1000000 - 0xf101ffff (0x20000) MX[B](B)
 [13] -1 0 0x90000000 - 0x9000ffff (0x10000) MX[B](B)
 [14] -1 0 0x98000000 - 0x9fffffff (0x8000000) MX[B](B)
 [15] -1 0 0x0000ffff - 0x0000ffff (0x1) IX[B]
 [16] -1 0 0x00000000 - 0x000000ff (0x100) IX[B]
 [17] -1 0 0xf0000400 - 0xf00004ff (0x100) IX[B](B)
(II) LoadModule: "extmod"
(II) Loading /usr/lib/xorg/modules/extensions//libextmod.so
(II) Module extmod: vendor="X.Org Foundation"
 compiled for 1.3.0, module version = 1.0.0
 Module class: X.Org Server Extension
 ABI class: X.Org Server Extension, version 0.3
(II) Loading extension SHAPE
(II) Loading extension MIT-SUNDRY-NONSTANDARD
(II) Loading extension BIG-REQUESTS
(II) Loading extension SYNC
(II) Loading extension MIT-SCREEN-SAVER
(II) Loading extension XC-MISC
(II) Loading extension XFree86-VidModeExtension
(II) Loading extension XFree86-Misc
(II) Loading extension XFree86-DGA
(II) Loading extension DPMS
(II) Loading extension TOG-CUP
(II) Loading extension Extended-Visual-Information
(II) Loading extension XVideo
(II) Loading extension XVideo-MotionCompensation
(II) Loading extension X-Resource
(II) LoadModule: "dbe"
(II) Loading /usr/lib/xorg/modules/extensions//libdbe.so
(II) Module dbe: vendor="X.Org Foundation"
 compiled for 1.3.0, module version = 1.0.0
 Module class: X.Org Server Extension
 ABI class: X.Org Server Extension, version 0.3
(II) Loading extension DOUBLE-BUFFER
(II) LoadModule: "glx"
(II) Loading /usr/lib/xorg/modules/extensions//libglx.so
(II) Module glx: vendor="X.Org Foundation"
 compiled for 1.3.0, module version = 1.0.0
 ABI class: X.Org Server Extension, version 0.3
(==) AIGLX enabled
(II) Loading extension GLX
(II) LoadModule: "freetype"
(II) Loading /usr/lib/xorg/modules//fonts/libfreetype.so
(II) Module freetype: vendor="X.Org Foundation & the After X-TT Project"
 compiled for 1.3.0, module version = 2.1.0
 Module class: X.Org Font Renderer
 ABI class: X.Org Font Renderer, version 0.5
(II) Loading font FreeType
(II) LoadModule: "record"
(II) Loading /usr/lib/xorg/modules/extensions//librecord.so
(II) Module record: vendor="X.Org Foundation"
 compiled for 1.3.0, module version = 1.13.0
 Module class: X.Org Server Extension
 ABI class: X.Org Server Extension, version 0.3
(II) Loading extension RECORD
(II) LoadModule: "dri"
(II) Loading /usr/lib/xorg/modules/extensions//libdri.so
(II) Module dri: vendor="X.Org Foundation"
 compiled for 1.3.0, module version = 1.0.0
 ABI class: X.Org Server Extension, version 0.3
(II) Loading extension XFree86-DRI
(II) LoadModule: "ati"
(II) Loading /usr/lib/xorg/modules/drivers//ati_drv.so
(II) Module ati: vendor="X.Org Foundation"
 compiled for 1.3.0, module version = 6.7.195
 Module class: X.Org Video Driver
 ABI class: X.Org Video Driver, version 1.2
(II) LoadModule: "kbd"
(II) Loading /usr/lib/xorg/modules/input//kbd_drv.so
(II) Module kbd: vendor="X.Org Foundation"
 compiled for 1.3.0, module version = 1.2.1
 Module class: X.Org XInput Driver
 ABI class: X.Org XInput driver, version 0.7
(II) LoadModule: "mouse"
(II) Loading /usr/lib/xorg/modules/input//mouse_drv.so
(II) Module mouse: vendor="X.Org Foundation"
 compiled for 1.3.0, module version = 1.2.1
 Module class: X.Org XInput Driver
 ABI class: X.Org XInput driver, version 0.7
(II) ATI: ATI driver wrapper (version 6.7.195) for chipsets: mach64, rage128, radeon
(II) Primary Device is: PCI 00:10:0
(II) Loading sub module "radeon"
(II) LoadModule: "radeon"
(II) Loading /usr/lib/xorg/modules/drivers//radeon_drv.so
(II) Module radeon: vendor="X.Org Foundation"
 compiled for 1.3.0, module version = 4.3.0
 Module class: X.Org Video Driver
 ABI class: X.Org Video Driver, version 1.2
(II) RADEON: Driver for ATI Radeon chipsets: ATI Radeon QD (AGP),
 ATI Radeon QE (AGP), ATI Radeon QF (AGP), ATI Radeon QG (AGP),
 ATI Radeon VE/7000 QY (AGP/PCI), ATI Radeon VE/7000 QZ (AGP/PCI),
 ATI ES1000 515E (PCI), ATI ES1000 5969 (PCI),
 ATI Radeon Mobility M7 LW (AGP),
 ATI Mobility FireGL 7800 M7 LX (AGP),
 ATI Radeon Mobility M6 LY (AGP), ATI Radeon Mobility M6 LZ (AGP),
 ATI Radeon IGP320 (A3) 4136, ATI Radeon IGP320M (U1) 4336,
 ATI Radeon IGP330/340/350 (A4) 4137,
 ATI Radeon IGP330M/340M/350M (U2) 4337,
 ATI Radeon 7000 IGP (A4+) 4237, ATI Radeon Mobility 7000 IGP 4437,
 ATI FireGL 8700/8800 QH (AGP), ATI Radeon 8500 QL (AGP),
 ATI Radeon 9100 QM (AGP), ATI Radeon 8500 AIW BB (AGP),
 ATI Radeon 8500 AIW BC (AGP), ATI Radeon 7500 QW (AGP/PCI),
 ATI Radeon 7500 QX (AGP/PCI), ATI Radeon 9000/PRO If (AGP/PCI),
 ATI Radeon 9000 Ig (AGP/PCI), ATI FireGL Mobility 9000 (M9) Ld (AGP),
 ATI Radeon Mobility 9000 (M9) Lf (AGP),
 ATI Radeon Mobility 9000 (M9) Lg (AGP),
 ATI Radeon 9100 IGP (A5) 5834,
 ATI Radeon Mobility 9100 IGP (U3) 5835, ATI Radeon 9100 PRO IGP 7834,
 ATI Radeon Mobility 9200 IGP 7835, ATI Radeon 9250 5960 (AGP),
 ATI Radeon 9200 5961 (AGP), ATI Radeon 9200 5962 (AGP),
 ATI Radeon 9200SE 5964 (AGP), ATI FireMV 2200 (PCI),
 ATI Radeon Mobility 9200 (M9+) 5C61 (AGP),
 ATI Radeon Mobility 9200 (M9+) 5C63 (AGP), ATI Radeon 9500 AD (AGP),
 ATI Radeon 9500 AE (AGP), ATI Radeon 9600TX AF (AGP),
 ATI FireGL Z1 AG (AGP), ATI Radeon 9700 Pro ND (AGP),
 ATI Radeon 9700/9500Pro NE (AGP), ATI Radeon 9600TX NF (AGP),
 ATI FireGL X1 NG (AGP), ATI Radeon 9600 AP (AGP),
 ATI Radeon 9600SE AQ (AGP), ATI Radeon 9600XT AR (AGP),
 ATI Radeon 9600 AS (AGP), ATI FireGL T2 AT (AGP),
 ATI FireGL RV360 AV (AGP),
 ATI Radeon Mobility 9600/9700 (M10/M11) NP (AGP),
 ATI Radeon Mobility 9600 (M10) NQ (AGP),
 ATI Radeon Mobility 9600 (M11) NR (AGP),
 ATI Radeon Mobility 9600 (M10) NS (AGP),
 ATI FireGL Mobility T2 (M10) NT (AGP),
 ATI FireGL Mobility T2e (M11) NV (AGP), ATI Radeon 9650,
 ATI Radeon 9800SE AH (AGP), ATI Radeon 9800 AI (AGP),
 ATI Radeon 9800 AJ (AGP), ATI FireGL X2 AK (AGP),
 ATI Radeon 9800PRO NH (AGP), ATI Radeon 9800 NI (AGP),
 ATI FireGL X2 NK (AGP), ATI Radeon 9800XT NJ (AGP),
 ATI Radeon X600 (RV380) 3E50 (PCIE),
 ATI FireGL V3200 (RV380) 3E54 (PCIE),
 ATI Radeon Mobility X600 (M24) 3150 (PCIE),
 ATI Radeon Mobility X300 (M24) 3152 (PCIE),
 ATI FireGL M24 GL 3154 (PCIE), ATI Radeon X300 (RV370) 5B60 (PCIE),
 ATI Radeon X600 (RV370) 5B62 (PCIE),
 ATI Radeon X550 (RV370) 5B63 (PCIE),
 ATI FireGL V3100 (RV370) 5B64 (PCIE),
 ATI FireMV 2200 PCIE (RV370) 5B65 (PCIE),
 ATI Radeon Mobility X300 (M22) 5460 (PCIE),
 ATI Radeon Mobility X600 SE (M24C) 5462 (PCIE),
 ATI FireGL M22 GL 5464 (PCIE), ATI Radeon XPRESS 200 5A41 (PCIE),
 ATI Radeon XPRESS 200M 5A42 (PCIE),
 ATI Radeon XPRESS 200 5A61 (PCIE),
 ATI Radeon XPRESS 200M 5A62 (PCIE),
 ATI Radeon XPRESS 200 5954 (PCIE),
 ATI Radeon XPRESS 200M 5955 (PCIE),
 ATI Radeon XPRESS 200 5974 (PCIE),
 ATI Radeon XPRESS 200M 5975 (PCIE), ATI FireGL V5000 (RV410) (PCIE),
 ATI Mobility FireGL V5000 (M26) (PCIE),
 ATI Mobility FireGL V5000 (M26) (PCIE),
 ATI Mobility Radeon X700 XL (M26) (PCIE),
 ATI Mobility Radeon X700 (M26) (PCIE),
 ATI Mobility Radeon X700 (M26) (PCIE),
 ATI Radeon X700 PRO (RV410) (PCIE),
 ATI Radeon X700 XT (RV410) (PCIE), ATI Radeon X700 (RV410) (PCIE),
 ATI Radeon X700 SE (RV410) (PCIE), ATI Radeon X700 SE (RV410) (PCIE),
 ATI Radeon X800 (R420) JH (AGP), ATI Radeon X800PRO (R420) JI (AGP),
 ATI Radeon X800SE (R420) JJ (AGP), ATI Radeon X800 (R420) JK (AGP),
 ATI Radeon X800 (R420) JL (AGP), ATI FireGL X3 (R420) JM (AGP),
 ATI Radeon Mobility 9800 (M18) JN (AGP),
 ATI Radeon X800XT (R420) JP (AGP), ATI Radeon X800 SE (R420) (AGP),
 ATI Radeon AIW X800 VE (R420) JT (AGP),
 ATI Radeon X800 (R423) UH (PCIE),
 ATI Radeon X800PRO (R423) UI (PCIE),
 ATI Radeon X800LE (R423) UJ (PCIE),
 ATI Radeon X800SE (R423) UK (PCIE),
 ATI FireGL V5100 (R423) UQ (PCIE),
 ATI FireGL unknown (R423) UR (PCIE),
 ATI FireGL unknown (R423) UT (PCIE),
 ATI Radeon X800XT (R423) 5D57 (PCIE), ATI FireGL V7100 (R423) (PCIE),
 ATI Mobility FireGL V5100 (M28) (PCIE),
 ATI Mobility Radeon X800 (M28) (PCIE),
 ATI Mobility Radeon X800 XT (M28) (PCIE),
 ATI Radeon X800 (R430) (PCIE), ATI Radeon X800 XL (R430) (PCIE),
 ATI Radeon X800 SE (R430) (PCIE), ATI Radeon X800 XTP (R430) (PCIE),
 ATI Radeon X850 5D4C (PCIE),
 ATI unknown Radeon / FireGL (R480) 5D50 (PCIE),
 ATI Radeon X850 SE (R480) (PCIE), ATI Radeon X850 PRO (R480) (PCIE),
 ATI Radeon X850 XT (R480) (PCIE),
 ATI Radeon X850 XT PE (R480) (PCIE),
 ATI Radeon X850 PRO (R480) (AGP), ATI Radeon X850 SE (R480) (AGP),
 ATI Radeon X850 XT (R480) (AGP), ATI Radeon X850 XT PE (R480) (AGP)
(--) Chipset ATI Radeon 9200 5962 (AGP) found
(II) resource ranges after xf86ClaimFixedResources() call:
 [0] -1 0 0x00100000 - 0x3fffffff (0x3ff00000) MX[B]E(B)
 [1] -1 0 0x000f0000 - 0x000fffff (0x10000) MX[B]
 [2] -1 0 0x000c0000 - 0x000effff (0x30000) MX[B]
 [3] -1 0 0x00000000 - 0x0009ffff (0xa0000) MX[B]
 [4] -1 0 0xf5200000 - 0xf53fffff (0x200000) MX[B]E
 [5] -1 0 0xf5000000 - 0xf5003fff (0x4000) MX[B]E
 [6] -1 0 0xf5004000 - 0xf5007fff (0x4000) MX[B]E
 [7] -1 0 0x80080000 - 0x80080fff (0x1000) MX[B]E
 [8] -1 0 0x80081000 - 0x80081fff (0x1000) MX[B]E
 [9] -1 0 0x80082000 - 0x80082fff (0x1000) MX[B]E
 [10] -1 0 0x80083000 - 0x80083fff (0x1000) MX[B]E
 [11] -1 0 0x80000000 - 0x8007ffff (0x80000) MX[B]E
 [12] -1 0 0xf1000000 - 0xf101ffff (0x20000) MX[B](B)
 [13] -1 0 0x90000000 - 0x9000ffff (0x10000) MX[B](B)
 [14] -1 0 0x98000000 - 0x9fffffff (0x8000000) MX[B](B)
 [15] -1 0 0x0000ffff - 0x0000ffff (0x1) IX[B]
 [16] -1 0 0x00000000 - 0x000000ff (0x100) IX[B]
 [17] -1 0 0xf0000400 - 0xf00004ff (0x100) IX[B](B)
(WW) ****INVALID IO ALLOCATION**** b: 0xf0000400 e: 0xf00004ff correcting
(EE) end of block range 0xefffffff < begin 0xf0000000
(II) window:
 [0] -1 0 0x00000000 - 0x0000ffff (0x10000) IX[B]
(II) resSize:
(II) window fixed:
 [0] -1 0 0x00000000 - 0x0000ffff (0x10000) IX[B]
(II) resource ranges after probing:
 [0] -1 0 0x00100000 - 0x3fffffff (0x3ff00000) MX[B]E(B)
 [1] -1 0 0x000f0000 - 0x000fffff (0x10000) MX[B]
 [2] -1 0 0x000c0000 - 0x000effff (0x30000) MX[B]
 [3] -1 0 0x00000000 - 0x0009ffff (0xa0000) MX[B]
 [4] -1 0 0xf5200000 - 0xf53fffff (0x200000) MX[B]E
 [5] -1 0 0xf5000000 - 0xf5003fff (0x4000) MX[B]E
 [6] -1 0 0xf5004000 - 0xf5007fff (0x4000) MX[B]E
 [7] -1 0 0x80080000 - 0x80080fff (0x1000) MX[B]E
 [8] -1 0 0x80081000 - 0x80081fff (0x1000) MX[B]E
 [9] -1 0 0x80082000 - 0x80082fff (0x1000) MX[B]E
 [10] -1 0 0x80083000 - 0x80083fff (0x1000) MX[B]E
 [11] -1 0 0x80000000 - 0x8007ffff (0x80000) MX[B]E
 [12] -1 0 0xf1000000 - 0xf101ffff (0x20000) MX[B](B)
 [13] -1 0 0x90000000 - 0x9000ffff (0x10000) MX[B](B)
 [14] -1 0 0x98000000 - 0x9fffffff (0x8000000) MX[B](B)
 [15] 0 0 0x000a0000 - 0x000affff (0x10000) MS[B]
 [16] 0 0 0x000b0000 - 0x000b7fff (0x8000) MS[B]
 [17] 0 0 0x000b8000 - 0x000bffff (0x8000) MS[B]
 [18] -1 0 0x00000400 - 0x000004ff (0x100) IX[B](B)
 [19] -1 0 0x0000ffff - 0x0000ffff (0x1) IX[B]
 [20] -1 0 0x00000000 - 0x000000ff (0x100) IX[B]
 [21] 0 0 0xf00003b0 - 0xf00003bb (0xc) IS[B]
 [22] 0 0 0xf00003c0 - 0xf00003df (0x20) IS[B]
(II) Setting vga for screen 0.
(II) RADEON(0): MMIO registers at 0x90000000: size 64KB
(II) RADEON(0): PCI bus 0 card 16 func 0
(**) RADEON(0): Depth 24, (--) framebuffer bpp 32
(II) RADEON(0): Pixel depth = 24 bits stored in 4 bytes (32 bpp pixmaps)
(==) RADEON(0): Default visual is TrueColor
(II) RADEON(0): VGAAccess option set to FALSE, VGA module load skipped
(==) RADEON(0): RGB weight 888
(II) RADEON(0): Using 8 bits per RGB (8 bit DAC)
(--) RADEON(0): Chipset: "ATI Radeon 9200 5962 (AGP)" (ChipID = 0x5962)
(--) RADEON(0): Linear framebuffer at 0x98000000
(--) RADEON(0): BIOS at 0xf1000000
(II) RADEON(0): AGP card detected
(II) Attempted to read BIOS 64KB from /sys/bus/pci/devices/0000:00:10.0/rom: got 0KB
(WW) RADEON(0): Video BIOS not detected in PCI space!
(WW) RADEON(0): Attempting to read Video BIOS from legacy ISA space!
(WW) RADEON(0): Unrecognized BIOS signature, BIOS data will not be used
drmOpenDevice: node name is /dev/dri/card0
drmOpenDevice: open result is 8, (OK)
drmOpenByBusid: Searching for BusID pci:0000:00:10.0
drmOpenDevice: node name is /dev/dri/card0
drmOpenDevice: open result is 8, (OK)
drmOpenByBusid: drmOpenMinor returns 8
drmOpenByBusid: drmGetBusid reports pci:0000:00:10.0
(II) RADEON(0): [dri] Found DRI library version 1.3.0 and kernel module version 1.24.0
(==) RADEON(0): Page Flipping disabled
(II) RADEON(0): Will try to use DMA for Xv image transfers
(II) RADEON(0): Generation 2 PCI interface, using max accessible memory
(II) RADEON(0): Detected total video RAM=32768K, accessible=131072K (PCI BAR=131072K)
(--) RADEON(0): Mapped VideoRAM: 32768 kByte (64 bit DDR SDRAM)
(II) RADEON(0): Color tiling enabled by default
(II) RADEON(0): Max desktop size set to 2048x1200
(II) RADEON(0): For a larger or smaller max desktop size, add a Virtual line to your xorg.conf
(II) RADEON(0): If you are having trouble with 3D, reduce the desktop size by adjusting the Virtual line to your xorg.conf
(II) Loading sub module "ddc"
(II) LoadModule: "ddc"(II) Module already built-in
(II) Loading sub module "i2c"
(II) LoadModule: "i2c"(II) Module already built-in
(WW) RADEON(0): Video BIOS not detected, using default clock settings!
(II) RADEON(0): Probed PLL values: xtal: 27.000000 Mhz, sclk: 249.750000 Mhz, mclk: 190.125000 Mhz
(II) RADEON(0): Output DVI-0 using monitor section SyncMaster
(II) RADEON(0): I2C bus "DVI_DDC" initialized.
(II) RADEON(0): Output VGA-0 has no monitor section
(II) RADEON(0): I2C bus "VGA_DDC" initialized.
(II) RADEON(0): Output S-video has no monitor section
(II) RADEON(0): Port0:
 Monitor -- AUTO
 Connector -- DVI-I
 DAC Type -- TVDAC/ExtDAC
 TMDS Type -- Internal
 DDC Type -- DVI_DDC
(II) RADEON(0): Port1:
 Monitor -- AUTO
 Connector -- VGA
 DAC Type -- Primary
 TMDS Type -- None
 DDC Type -- VGA_DDC
(II) RADEON(0): Port2:
 Monitor -- AUTO
 Connector -- STV
 DAC Type -- TVDAC/ExtDAC
 TMDS Type -- None
 DDC Type -- None
(II) RADEON(0): I2C device "DVI_DDC:ddc2" registered at address 0xA0.
(II) RADEON(0): I2C device "DVI_DDC:ddc2" removed.
(II) RADEON(0): I2C device "DVI_DDC:ddc2" registered at address 0xA0.
(II) RADEON(0): I2C device "DVI_DDC:ddc2" removed.
(II) RADEON(0): I2C device "DVI_DDC:ddc2" registered at address 0xA0.
(II) RADEON(0): I2C device "DVI_DDC:ddc2" removed.
(II) RADEON(0): DDC Type: 2, Detected Monitor Type: 0
(II) RADEON(0): Detected Monitor Type: 0
finished output detect: 0
(II) RADEON(0): I2C device "VGA_DDC:ddc2" registered at address 0xA0.
(II) RADEON(0): I2C device "VGA_DDC:ddc2" removed.
(II) RADEON(0): I2C device "VGA_DDC:ddc2" registered at address 0xA0.
(II) RADEON(0): I2C device "VGA_DDC:ddc2" removed.
(II) RADEON(0): I2C device "VGA_DDC:ddc2" registered at address 0xA0.
(II) RADEON(0): I2C device "VGA_DDC:ddc2" removed.
(II) RADEON(0): DDC Type: 3, Detected Monitor Type: 0
finished output detect: 1
finished output detect: 2
finished all detect
before xf86InitialConfiguration
(II) RADEON(0): I2C device "DVI_DDC:ddc2" registered at address 0xA0.
(II) RADEON(0): I2C device "DVI_DDC:ddc2" removed.
(II) RADEON(0): I2C device "DVI_DDC:ddc2" registered at address 0xA0.
(II) RADEON(0): I2C device "DVI_DDC:ddc2" removed.
(II) RADEON(0): I2C device "DVI_DDC:ddc2" registered at address 0xA0.
(II) RADEON(0): I2C device "DVI_DDC:ddc2" removed.
(II) RADEON(0): DDC Type: 2, Detected Monitor Type: 0
(II) RADEON(0): Detected Monitor Type: 0
(II) RADEON(0): Output DVI-0 disconnected
(II) RADEON(0): EDID for output DVI-0
(II) RADEON(0): I2C device "VGA_DDC:ddc2" registered at address 0xA0.
(II) RADEON(0): I2C device "VGA_DDC:ddc2" removed.
(II) RADEON(0): I2C device "VGA_DDC:ddc2" registered at address 0xA0.
(II) RADEON(0): I2C device "VGA_DDC:ddc2" removed.
(II) RADEON(0): I2C device "VGA_DDC:ddc2" registered at address 0xA0.
(II) RADEON(0): I2C device "VGA_DDC:ddc2" removed.
(II) RADEON(0): DDC Type: 3, Detected Monitor Type: 0
(II) RADEON(0): Output VGA-0 disconnected
(II) RADEON(0): EDID for output VGA-0
(II) RADEON(0): Output S-video disconnected
(II) RADEON(0): EDID for output S-video
(II) RADEON(0): Output DVI-0 disconnected
(II) RADEON(0): Output VGA-0 disconnected
(II) RADEON(0): Output S-video disconnected
(EE) RADEON(0): No valid modes.
(II) UnloadModule: "ati"
(II) UnloadModule: "radeon"
(EE) Screen(s) found, but none have a usable configuration.

Fatal server error:
no screens found

Hi, can you tell us exactly which is your Radeon video card model?
Radeon 9200?
lspci command could help, post here the output.

Mara

0000:00:10.0 VGA compatible controller: ATI Technologies Inc RV280 [Radeon 9200] (rev 01) (prog-if 00 [VGA])
        Subsystem: ATI Technologies Inc RV280 [Radeon 9200]
        Flags: bus master, 66MHz, medium devsel, latency 255, IRQ 48
        Memory at 98000000 (32-bit, prefetchable) [size=128M]
        I/O ports at f0000400 [size=256]
        Memory at 90000000 (32-bit, non-prefetchable) [size=64K]
        Expansion ROM at f1000000 [size=128K]
        Capabilities: [58] AGP version 2.0
        Capabilities: [50] Power Management version 2

You can try to reconfigure xorg with the command

sudo dpkg-reconfigure -phigh xserver-xorg

I Haven't been able to generate an xorg.conf that works.

The part I'm most confused about from the log :

(EE) RADEON(0): No valid modes.

how do I find out what to change in my display settings?

Try to delete the xorg.conf (backup it). Normally, the xserver should find its way without it now (your keyboard will be considered as QWERTY)

This produced the same output.

I also tried using VESA and VGA, and ended up with the same

(EE) Screen(s) found, but none have a usable configuration.

Thanks Olivier, that solved my question.