Strange Image Flicker

[Michael73]

In the last 2 days I've started noticing a strange flickering with images loading in Safari both static and in-line video e.g. cnn.com. Today at lunch while home I opened both Safari and Firefox, opened cnn.com and then clicked on a video regarding Tori Spelling and how everyone was sleeping with everyone else on 90210. With both videos playing at the same time it looked fine in Firefox but flickered in Safari. I've noticed the same issue with static image loads too. In FF the image loads no problem, in Safari it flickers. I don't think this is related to the video card (8800GT) but sounds like a software issue to me.

Anyone else having a similar problem with a similar rig (see my sig below)? BTW, I'm running 10.5.2 with all the latest updates.