I can confirm this bug still exists. 12.04 with all updates, Compiz 1:0.9.7.8-0ubuntu1.4, Unity 5.16.0-0ubuntu1+karosdev2.
With desktop cube "opacity when not rotating" set to <100%, fullscreen has unity panel visible but unusable at all times.
With desktop cube "opacity when not rotating" set to 100%, fullscreen works correctly.
I can confirm this bug still exists. 12.04 with all updates, Compiz 1:0.9.7. 8-0ubuntu1. 4, Unity 5.16.0- 0ubuntu1+ karosdev2.
With desktop cube "opacity when not rotating" set to <100%, fullscreen has unity panel visible but unusable at all times.
With desktop cube "opacity when not rotating" set to 100%, fullscreen works correctly.
-AG