Karmic 9.10 Network collisions SIS191 on Gbit

I just installed 9.10 and my internal laptop network card is recognised and I CAN surf the net on a wired interface. (when I set the MTU to 1250 or so)

only problem is that I have an instable connections (my guess is due collisions.)
My router is a Gbit router.. so I have a gbit connection to my DIR 655..
When I use my laptop directly to my WAN.. (which is 100 mbit) I have no collisions and the connection is perfect..
When my router comes in between.. the system recognises the gbit connection and then I have collisions.
My guess is that the sis191 driver doesnt handle gbit connections that well.

I tried forcing ubuntu to work on 100 mbit instead of the gbit..
but if I force ubuntu to use 100 mbit (in ethtool it state it uses 100 mbit.. but in dmesg is says 1000 mbit.)

hoos@Asus:/etc/init.d$ sudo mii-tool -F 100baseTx-FD
hoos@Asus:/etc/init.d$ sudo mii-tool
eth0: negotiated 1000baseT-FD flow-control, link ok

hoos@Asus:/etc/wicd$ sudo /usr/sbin/ethtool -s eth0 speed 100 duplex full
hoos@Asus:/etc/wicd$
[27620.040522] ADDRCONF(NETDEV_UP): wlan0: link is not ready
[27630.148037] eth0: mii ext = 0000.
[27630.172035] eth0: mii lpa=cde1 adv=01e1 exp=000d.
[27630.188030] eth0: link on 1000 Mbps Full Duplex mode.
[27630.284030] eth0: mii ext = 0000.
[27630.308030] eth0: mii lpa=cde1 adv=01e1 exp=000d.
[27630.324034] eth0: link on 1000 Mbps Full Duplex mode.
hoos@Asus:/etc$
hoos@Asus:/etc$ uname -a
Linux Asus 2.6.31-14-generic #48-Ubuntu SMP Fri Oct 16 14:04:26 UTC 2009 i686 GNU/Linux
hoos@Asus:/etc$
[sudo] password for hoos:
00:00.0 Host bridge: Silicon Integrated Systems [SiS] 671MX
00:01.0 PCI bridge: Silicon Integrated Systems [SiS] PCI-to-PCI bridge
00:02.0 ISA bridge: Silicon Integrated Systems [SiS] SiS968 [MuTIOL Media IO] (rev 01)
00:02.5 IDE interface: Silicon Integrated Systems [SiS] 5513 [IDE] (rev 01)
00:03.0 USB Controller: Silicon Integrated Systems [SiS] USB 1.1 Controller (rev 0f)
00:03.1 USB Controller: Silicon Integrated Systems [SiS] USB 1.1 Controller (rev 0f)
00:03.3 USB Controller: Silicon Integrated Systems [SiS] USB 2.0 Controller
00:04.0 Ethernet controller: Silicon Integrated Systems [SiS] 191 Gigabit Ethernet Adapter (rev 02)
00:05.0 IDE interface: Silicon Integrated Systems [SiS] SATA Controller / IDE mode (rev 03)
00:06.0 PCI bridge: Silicon Integrated Systems [SiS] PCI-to-PCI bridge
00:07.0 PCI bridge: Silicon Integrated Systems [SiS] PCI-to-PCI bridge
00:0f.0 Audio device: Silicon Integrated Systems [SiS] Azalia Audio Controller
01:00.0 VGA compatible controller: ATI Technologies Inc Mobility Radeon HD 3400 Series
02:00.0 Network controller: Atheros Communications Inc. AR928X Wireless Network Adapter (PCI-Express) (rev 01)
hoos@Asus:~$ ifconfig
eth0 Link encap:Ethernet HWaddr 00:24:8c:1e:b6:08
inet addr:192.168.0.195 Bcast:192.168.0.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1250 Metric:1
RX packets:176981 errors:0 dropped:0 overruns:0 frame:0
TX packets:90251 errors:0 dropped:0 overruns:0 carrier:0
collisions:1203 txqueuelen:1000
RX bytes:222996008 (222.9 MB) TX bytes:6143432 (6.1 MB)
Interrupt:19 Base address:0xdead

Update: I tried a new CAT6 cable to rule out any cable issues, unf. no effect.

any ideas ?

Thanks in advance for any comments!

Hoos