Why Does My Screen Twitch (mostly corners please help)

[amatoof]

im running on a SiS 315 XP Phantom Pro and why does my screen twitch i know it has something to do with the refresh rate but i cant quite get it to stop shaking at the corners. this comp is brand new i build my own its a amd athlon 1700+/256 DDR Memory/Shuttle AKA31/SiS315 Farley new also i know i have a power supply problem im fixing that could that be a reason why maybe my cards over heating please help me.

[Density Duck]

I am almost certain that your speakers hugging your monitor a little too tightly. Try moving them away and you should see a difference.