I've been having this problem for a little while, getting artefacts in different areas, all during scrolling. In the screenshot you'll see the worst of it in stacks, but it happens in Adium frequently when scrolling through a chat or contact list.
This was the beginning of the problem I had with my iMac right before it bit the dust. I'm afraid of it escalating, guys; I need some advice.
This was the beginning of the problem I had with my iMac right before it bit the dust. I'm afraid of it escalating, guys; I need some advice.