This worked for my Radeon VE 7000:

Section "Device"
### Available Driver options are:-
# sw_cursor is needed for some ati and radeon cards
#Option "sw_cursor"
#Option "hw_cursor"
#Option "NoAccel"
#Option "ShowCache"
#Option "ShadowFB"
#Option "UseFBDev"
#Option "Rotate"
Identifier "Card0"
# The following line is auto-generated by KNOPPIX mkxf86config
Driver "ati"
VendorName "ati"
BoardName "radeon"
# BusID "PCI:1:0:0"
EndSection

Section "Screen"
Identifier "Screen0"
Device "Card0"
Monitor "Monitor0"
DefaultColorDepth 24
SubSection "Display"
Depth 1
Modes "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 4
Modes "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 8
Modes "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 15
Modes "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 16
Modes "1208x1024" "1024x768" "800x600"
EndSubSection
SubSection "Display"
Depth 24
Modes "1280x1024" "1024x768" "800x600"
EndSubSection
SubSection "Display"
Depth 32
Modes "1280x1024" "1024x768" "800x600"
EndSubSection
EndSection