Yo,
When I switch to fullscreen mode in DOSBox .72, the screen gets all weird, for two sec.s and then turns normal. then, as soon as I do anything, the colours get inverted around the moving part of the screen.
Also, when playing games where the whole screen move (Abuse and Doom, namely) sometimes my framerate drops to something like 2 sec/frame and each frame the game get a shade of blue, green or red, which updates one pixel at a time. What's wrong here?

I found a solution, which is to open and close fullscreen mode a few times, but is there an easier way?

specs:
Vista home premium
2 GB RAM
AMD Turion64 X2 tl-56 1.8 GHz
NVIDIA GeForce 8400M GS