ati - Gnome-Shell and Unity run at the same time

I have installed Ubuntu Oneiric and everything seemed to work fine, downloaded binary ATI Catalyst 11.9. After that installed Gnome Shell. Typed in Terminakl gnome-shell --replace but still there are problems, seems like unity is disturbing Gnome Shell, when I point my mouse to the top left of the screen which opens Applications/Windows menu. Last time somehow managed to uninstall unity completely and for the moment Gnome-Shell worked properly, but after reboot, everything crashed, wasn't even able to boot in. Any ideas ? Seemed for me like Unity was trying to show it's panel in the top of Gnome-Shell's panel.