fullscreen = true
width = 1920
height = 1080
refreshrate = 60
vsync = false
If this doesn't work, you can try to edit the screen.dat file with vsync ACTIVATED, that is, replace the last line with
vsync = true
This may be useful, apparently, mostly to laptop users and/or people whose PCs (especially the GPU) are slightly outdated. It solved the problem on a 15.6' HP Pavilion DV6000 laptop with a Geforce Go 7400 (256 MB, DX9.0c) and 1280x800 resolution.
Set MSAA settings to 'use application defaults'.