bem, fiz a atualização do 8.04 pro 8.10 coloquei o xorg como vc falou mas não funcionu, tentei das duas maneiras aqui postas porem nenhuma deu certo.
meu xorg está assim no momento
Section "Module"
Load "glx"
Disable "dri2"
Load "dbe"
Load "extmod"
Load "type1"
Load "freetype"
EndSection
Section "Monitor"
# HorizSync source: builtin, VertRefresh source: builtin
Identifier "Monitor0"
VendorName "Unknown"
ModelName "TV-0"
HorizSync 28.0 - 55.0
VertRefresh 43.0 - 72.0
Option "DPMS"
EndSection
Section "Device"
Identifier "Device0"
Driver "nvidia"
VendorName "NVIDIA Corporation"
BoardName "GeForce 7900 GS"
EndSection
Section "Screen"
Identifier "Screen0"
Device "Device0"
Monitor "Monitor0"
DefaultDepth 24
Option "TVStandard" "480i"
Option "TVOutFormat" "COMPOSITE"
Option "TwinView" "1"
Option "metamodes" "TV: 640x480 +1024x768+0, DFP: nvidia-auto-select +0+0"
SubSection "Display"
Depth 24
EndSubSection
EndSection