Recompiling xorg-xserver source package without 120_fedora_disable_offscreen_pixmaps.diff has solved the problem, EXA & Compiz now function together. Unfortunately, restarting X/switching to VTs while Compiz is active causes my system to hang (but this happens also with XAA, so it's a matter for another bug).
Resolved.
Recompiling xorg-xserver source package without 120_fedora_ disable_ offscreen_ pixmaps. diff has solved the problem, EXA & Compiz now function together. Unfortunately, restarting X/switching to VTs while Compiz is active causes my system to hang (but this happens also with XAA, so it's a matter for another bug).