Video Card or monitor???

[slipperyslope]

I have noticed, when I have a dark background, I have "waves" running from my left top corner to the bottom right corner and back. I can really only notice this when I have a darker color on the screen. They switch direction every few seconds. I don't have any speakers around my monitor. I have also put on a snap on choke on the video cable and that doesn't help. The first time I noticed it was when my computer went through the bios.

Would you say this is the monitor or the video card causing the problem?

I have a CTX Ultra Screen PR700 and a VisionTek G2 ultra.

Jim