I also experience that compiz.real is using the CPU intensly when using the gnome-fast-user-switching-applet.
I login as user A (which uses compiz) and then switch to user B. User B has no problems. Then I switch back to user A again and after unlocking the screen the desktop is almost unusable.
Doing ALT-F2 and "metacity --replace" is the only way I've found to bring back my desktop without logging out and back in again.
I also experience that compiz.real is using the CPU intensly when using the gnome-fast- user-switching- applet.
I login as user A (which uses compiz) and then switch to user B. User B has no problems. Then I switch back to user A again and after unlocking the screen the desktop is almost unusable.
Doing ALT-F2 and "metacity --replace" is the only way I've found to bring back my desktop without logging out and back in again.