lower display resolution after upgrading to karmic

I've had similar problems in the past and I've found the output of "xrandr --verbose" to be useful to identify the problem. Not sure that it'll help but it might so suggest you post it here. The first line specifically will probably say something like "Screen 0: minimum 320 x 200, current 1024 x 600, maximum 2048 x 2048" (my output) but it's worth looking through it all. There's a "virtual" option you can put in xorg.conf to help if your max size is limited.

Same problem. Also with an Intel Controller:

00:02.0 VGA compatible controller: Intel Corporation Mobile 915GM/GMS/910GML Express Graphics Controller (rev 03)
00:02.1 Display controller: Intel Corporation Mobile 915GM/GMS/910GML Express Graphics Controller (rev 03)

xrandr --verbose shows that the current resolution is what's listed in the modes ....

xrandr --verbose
Screen 0: minimum 320 x 200, current 1280 x 1024, maximum 4096 x 4096
VGA1 connected 1280x1024+0+0 (0x3f) normal (normal left inverted right x axis y axis) 388mm x 291mm
        Identifier: 0x3b
        Timestamp: 121560
        Subpixel: unknown
        Clones:
        CRTC: 0
        CRTCs: 0 1
        Transform: 1.000000 0.000000 0.000000
                    0.000000 1.000000 0.000000
                    0.000000 0.000000 1.000000
                   filter:
        EDID_DATA:
                00ffffffffffff0010ac5b514b353830
                190801010e261d96e80dc9a057479827
                12484ca54b003159455961598199a94f
                a95901010101100bd0b4205e6310126c
                620884231100001a000000ff00353533
                3437413038354b36380a000000fc0044
                454c4c20443136323648540a000000fd
                0032a01e6bff000a2020202020200058
  1280x1024 (0x3f) 135.0MHz +HSync +VSync *current
        h: width 1280 start 1296 end 1440 total 1688 skew 0 clock 80.0KHz
        v: height 1024 start 1025 end 1028 total 1066 clock 75.0Hz
  1024x768 (0x40) 78.8MHz +HSync +VSync
        h: width 1024 start 1040 end 1136 total 1312 skew 0 clock 60.1KHz
        v: height 768 start 769 end 772 total 800 clock 75.1Hz

Same problem. Also with an Intel Controller:

00:02.0 VGA compatible controller: Intel Corporation Mobile 915GM/GMS/910GML Express Graphics Controller (rev 03)
00:02.1 Display controller: Intel Corporation Mobile 915GM/GMS/910GML Express Graphics Controller (rev 03)

xrandr --verbose shows that the current resolution is what's listed in the modes ....

xrandr --verbose
Screen 0: minimum 320 x 200, current 1280 x 1024, maximum 4096 x 4096
VGA1 connected 1280x1024+0+0 (0x3f) normal (normal left inverted right x axis y axis) 388mm x 291mm
        Identifier: 0x3b
        Timestamp: 121560
        Subpixel: unknown
        Clones:
        CRTC: 0
        CRTCs: 0 1
        Transform: 1.000000 0.000000 0.000000
                    0.000000 1.000000 0.000000
                    0.000000 0.000000 1.000000
                   filter:
        EDID_DATA:
                00ffffffffffff0010ac5b514b353830
                190801010e261d96e80dc9a057479827
                12484ca54b003159455961598199a94f
                a95901010101100bd0b4205e6310126c
                620884231100001a000000ff00353533
                3437413038354b36380a000000fc0044
                454c4c20443136323648540a000000fd
                0032a01e6bff000a2020202020200058
  1280x1024 (0x3f) 135.0MHz +HSync +VSync *current
        h: width 1280 start 1296 end 1440 total 1688 skew 0 clock 80.0KHz
        v: height 1024 start 1025 end 1028 total 1066 clock 75.0Hz
  1024x768 (0x40) 78.8MHz +HSync +VSync
        h: width 1024 start 1040 end 1136 total 1312 skew 0 clock 60.1KHz
        v: height 768 start 769 end 772 total 800 clock 75.1Hz

Mmmm, running xrandr --verbose says

Screen 0: minimum 320 x 200, current 1024 x 768, maximum 4096 x 4096
VGA1 connected 1024x768+0+0 (0x3c) normal (normal left inverted right x axis y axis) 312mm x 234mm
 Identifier: 0x3b
 Timestamp: 89226
 Subpixel: unknown
 Clones:
 CRTC: 0
 CRTCs: 0 1
 Transform: 1.000000 0.000000 0.000000
             0.000000 1.000000 0.000000
             0.000000 0.000000 1.000000
            filter:
 EDID_DATA:
  00ffffffffffff004c2d270037314e41
  130d01036820186b2a1269a552499924
  0e484ca4000031403159455961598180
  010101010101ea240060410028303060
  130038ea1000001e000000fd0032a01e
  470b000a202020202020000000fc0053
  796e634d61737465720a2020000000ff
  00485841573531303138310a202000fb
  1024x768 (0x3c) 94.5MHz +HSync +VSync *current +preferred
        h: width 1024 start 1072 end 1168 total 1376 skew 0 clock 68.7KHz
        v: height 768 start 769 end 772 total 808 clock 85.0Hz
  640x480 (0x3d) 31.5MHz -HSync -VSync
        h: width 640 start 656 end 720 total 840 skew 0 clock 37.5KHz
        v: height 480 start 481 end 484 total 500 clock 75.0Hz
  640x480 (0x3e) 25.2MHz -HSync -VSync
        h: width 640 start 656 end 752 total 800 skew 0 clock 31.5KHz
        v: height 480 start 490 end 492 total 525 clock 60.0Hz
  720x400 (0x3f) 28.3MHz -HSync +VSync
        h: width 720 start 738 end 846 total 900 skew 0 clock 31.5KHz
        v: height 400 start 412 end 414 total 449 clock 70.1Hz

No mention of the 1280x1024 mode.

Loading the previous kernel with grub, I get my old resolution. xrandr --verbose said

Screen 0: minimum 320 x 200, current 1280 x 1024, maximum 2048 x 2048
VGA connected 1280x1024+0+0 (0x3d) normal (normal left inverted right x axis y axis) 312mm x 234mm
 Identifier: 0x3b
 Timestamp: 90285
 Subpixel: unknown
 Clones:
 CRTC: 0
 CRTCs: 0 1
 Transform: 1.000000 0.000000 0.000000
             0.000000 1.000000 0.000000
             0.000000 0.000000 1.000000
            filter:
 EDID_DATA:
  00ffffffffffff004c2d270037314e41
  130d01036820186b2a1269a552499924
  0e484ca4000031403159455961598180
  010101010101ea240060410028303060
  130038ea1000001e000000fd0032a01e
  470b000a202020202020000000fc0053
  796e634d61737465720a2020000000ff
  00485841573531303138310a202000fb
  1024x768 (0x3c) 94.5MHz +HSync +VSync +preferred
        h: width 1024 start 1072 end 1168 total 1376 skew 0 clock 68.7KHz
        v: height 768 start 769 end 772 total 808 clock 85.0Hz
  1280x1024 (0x3d) 108.0MHz +HSync +VSync *current
        h: width 1280 start 1328 end 1440 total 1688 skew 0 clock 64.0KHz
        v: height 1024 start 1025 end 1028 total 1066 clock 60.0Hz
  1024x768 (0x3c) 94.5MHz +HSync +VSync
        h: width 1024 start 1072 end 1168 total 1376 skew 0 clock 68.7KHz
        v: height 768 start 769 end 772 total 808 clock 85.0Hz
  800x600 (0x3e) 56.2MHz +HSync +VSync
        h: width 800 start 832 end 896 total 1048 skew 0 clock 53.7KHz
        v: height 600 start 601 end 604 total 631 clock 85.1Hz
  640x480 (0x3f) 36.0MHz -HSync -VSync
        h: width 640 start 696 end 752 total 832 skew 0 clock 43.3KHz
        v: height 480 start 481 end 484 total 509 clock 85.0Hz
  640x480 (0x40) 31.5MHz -HSync -VSync
        h: width 640 start 656 end 720 total 840 skew 0 clock 37.5KHz
        v: height 480 start 481 end 484 total 500 clock 75.0Hz
  640x480 (0x41) 25.2MHz -HSync -VSync
        h: width 640 start 656 end 752 total 800 skew 0 clock 31.5KHz
        v: height 480 start 490 end 492 total 525 clock 59.9Hz
  720x400 (0x42) 28.3MHz -HSync +VSync
        h: width 720 start 738 end 846 total 900 skew 0 clock 31.5KHz
        v: height 400 start 412 end 414 total 449 clock 70.1Hz

But I don't think that's a solution; for that, I'd rather not upgrade to karmic.

Well if a new kernel is restricting your resolution, that strikes me as
a bug (but I'm not a dev so I could be mistaken). Out of interest, are
you able to add the missing mode eg as follows? (you can get the modeline using 'cvt')

xrandr --newmode "1280x1024_60.00" 109.00 1280 1368 1496 1712 1024
1027 1034 1063 -hsync +vsync

then

xrandr --addmode VGA 1280x1024_60.00

then

xrandr --output VGA --mode 1280x1024_60.00

I had the same problem with an intel chips set. I found that creating a new xorg.conf file to help Xorg worked:

1. Determine the modeline(s) for your monitor.

Use http://xtiming.sourceforge.net/cgi-bin/xtiming.pl

You may need to look at your monitor's manual, or, what worked best for me, was to google for my monitor. I was able to fill in enough details to get a usable modeline.

Modeline "1024x768@60" 64.56 1024 1056 1296 1328 768 783 791 807 +hsync -vsync

2. Turn off X11

$ sudo stop kdm

3. Reconfigure X11

In a virtual terminal, log in and:

$ cd /etc/X11
$ # backup existing xorg.conf file if exists
$ sudo mv xorg.conf xorg.conf.20091031 # xorg.conf may not exist
$ sudo Xorg -configure
$ sudo mv xorg.conf.new xorg.conf

In the section "Monitor", add the mode line:

Section "Monitor"
       # keep other lines here
       Modeline "1024x768@60" 64.56 1024 1056 1296 1328 768 783 791 807 +hsync -vsync
EndSection

And under the "Screen" section, add a reference to your new modeline:

Section "Screen"
      # keep other lines here
      SubSection "Display"
              Modes "1024x768@60"
              Viewport 0 0
              Depth 24
      EndSubSection

4. Restart Xorg

$ sudo start kdm

5. Parting thoughts
  a) This is an annoying regression. 9.04 did not have this problem with Intel graphics.
  b) The +hsync and -vsync options were trial and error. If you find horizontal blurring, trying +hsync
  c) Remember, your modeline is resolution and monitor dependent! Take care with step 1

I hope this helps!