I can confirm this bug. The problem emerged since I updated to 9.04. I also have an ATI HD 4850, Compiz enabled. After some hours Xorg uses several GBs of memory. It takes noticably longer compared to 8.04 to maximize/minimize windows (it seems to hang for 2 seconds, then the window appears). Xorg is using almost 100% of one core (I have 4).
I can confirm this bug. The problem emerged since I updated to 9.04. I also have an ATI HD 4850, Compiz enabled. After some hours Xorg uses several GBs of memory. It takes noticably longer compared to 8.04 to maximize/minimize windows (it seems to hang for 2 seconds, then the window appears). Xorg is using almost 100% of one core (I have 4).