Probeer dit eens:
With ubuntu 8.04, dpkg-reconfigure xserver-xorg is not the same anymore, now you can install your keybord and more with this.
But your videocard and monitor goes like this,
start in safe mode,
choose the last options with the "Try to fix X-server",
Here ubuntu will search and identify your monitor and videocard, so you have all your posssible settings.
Then reboot and install your videcard driver.(i use envy for this).
