I've sent Khaled a private message here on the forum alerting him to this problem.
I'm still trying to work out the exact criteria for which the problem happens. So far the easiest way for me to reproduce it is to do something like this:
1. Join 2-3 channels with people in them
2. Let people chat for a while, so that there's a few pages of scrollback in each channel window
3. Pick a channel window and bring it to the foreground
4. Move your mouse cursor over one of the other channel windows but DO NOT bring it to the foreground (i.e. do not click) -- just keep your mouse cursor over it
5. Use your scroll wheel to scroll back through the chat log of the non-foreground window
6. While keeping your mouse cursor over the same non-foreground window, move your cursor over nicknames said in chat who happen to be in the channel presently, or hotlinks (e.g.
http://blah/), or anything else that changes the cursor into a hand
7. Watch that non-foreground window carefully for flicker
For me anyway, I can reproduce the problem consistently using the above method.
