[adamfishercox]

Check out the video:

http://adamfishercox.com/Flickerssm.mov

Seen this before? Can I fix it short of a graphics card replacement?

[seanc]

It only seems to happen in Safari from what I can see. It looks like it could be more of a Safari or driver issue.
Graphics card/vram issues usually represent them of scrambling or lines.

Vista frequently gives me black boxes for menus, I know the graphics card is alright though, it's just a driver/Vista issue.

[CharlesS]

Check your Console to see if anything's getting logged that could be relevant.

[Chuckit]

I've seen bad RAM do that before. Not the most likely culprit, but it is apparently possible.

[adamfishercox]

no, I'd happens systemwide. Console doesnt provide anything relevant.