Same problem with Ubuntu 11.10 Unity 64bit, ATI 5750 and open source drivers.
On a left-right screen configuration left screen render the effect correctly while the right screen is corrupted (like in Stéphane screenshot) and doesn't accept mouse input while I would expect Expo to mirror the effect and accept input from either screen.
Changing "Multi Monitor Mode" setting in compiz Expo doesn't make any difference.
Same problem with Ubuntu 11.10 Unity 64bit, ATI 5750 and open source drivers.
On a left-right screen configuration left screen render the effect correctly while the right screen is corrupted (like in Stéphane screenshot) and doesn't accept mouse input while I would expect Expo to mirror the effect and accept input from either screen.
Changing "Multi Monitor Mode" setting in compiz Expo doesn't make any difference.