I can confirm the behaviour David JB is seeing -- it doesn't happen all the time, and doesn't seem to be reproducible, but Compiz (both the Dash and the various launcher overlays) appear underneath windows and steal focus. It doesn't matter for me if the window is full-screen, maximized, or un-maximized.
Using Ubuntu 11.04 64-bit, Compiz 3.8.16, on an Intel 3400 series onboard a Core i3.
I can confirm the behaviour David JB is seeing -- it doesn't happen all the time, and doesn't seem to be reproducible, but Compiz (both the Dash and the various launcher overlays) appear underneath windows and steal focus. It doesn't matter for me if the window is full-screen, maximized, or un-maximized.
Using Ubuntu 11.04 64-bit, Compiz 3.8.16, on an Intel 3400 series onboard a Core i3.