Alt+Tab does not work

Hello!

I have a problem with my window switch function.
It simply does not work for some days.
I changed nothing special… just updates.
I read some other threads but it were not helpful.

So here are some basic information:
OS: openSUSE 11.2
Windowmanager: KDE 4.3.1
Yes i have compiz but the settings are not very helpful, because i can’t define the key bindings.

I hope you have an idea.

best regards