mulittouch gestures gone after compiz reinstall - dell xps sputnik

Last week, my dell xps ubuntu developer edition arrived. Since then I've played around with all possible settings. I managed to unintentionally mess up some compiz settings and ended up reinstalling compiz. This was propably not such a good idea...2 hours later everything is back to normal except for my beloved multitouch gestures (3 fingers open resize, 4 fingers opens dash,...). How can I re-enable them? I've been googling for more then an hour without success.

Thanks in advance for your help!