One problem that I’ve had with Fedora 12 is that when enabling compliz the focus starts to follow the mouse pointer. This behavior is annoying to me as I don’t like events to occur unless I explicitly ask for them (aka click).
To disable this feature, perform the following:
1. install control-center-extra
2. Open with Applications -> System Tools -> Configuration Editor
3. Select the checkbox at /apps/compiz/general/allscreens/options/click_to_focus
That worked for me.