Intermittent freezing when scrolling under Compiz
After long enough uptime, some applications will start to freeze when I try to scroll. X pegs the CPU and becomes almost completely unresponsive (both input and display) until the redraw is finished, which can take 10~20s or up to a minute. (It takes much longer if I used the mousewheel, as the app tries to redraw once for every wheel click.) It doesn't matter if I scrolled only a line with an arrow key or all the way to the end of a document with End. Restarting Compiz or reverting to Metacity seems to fix the problem, which is why I suspect it's involved somehow. If I stick with Compiz, the issue will reappear after some time.