Try to install the correct drivers for your monitor.If this cannot be done try the windows drivers for the equivilent such as if your monitor supports 1280x1024 try an use svga 1280x1024 ect... This may help other wise d/l the correct ones from the net.
There are many in the windows database,just go to display properties/advanced monitor /change and browse through there and see if there is one for your monitor,Good Luck.
I am sure to use the correct driver for my monitor. Games work well with my previous ATI Rage Pro graphic card are not running in full screen with Voodoo3 3000. For example, the opening demo in NFS4 is having this problem, but it works fine during the racing using the resolution 1024x768.