Apparently VIA chips arent known for their linux friendliness
Youll have to try manually configuring it , goto Terminal , Applications >> Accesories >> Terminal , type
sudo gedit /etc/X11/xorg.conf
then your root password
it will open the xorg file in the text editor
You might have something like this
Section "Screen"
Identifier "Default Screen"
Device "Configured Video Device"
Monitor "Configured Monitor"
Defaultdepth 24
SubSection "Display"
Depth 24
Virtual 640 480
Modes "
[email protected]" "
[email protected]"
EndSubSection
EndSection
In modes add "
[email protected]"
Also try changing "vesa" in the device section to "via"
Save and restart