A couple of days ago, I updated my system from 11.10 to 12.04 LTS. Which, fortunately, solved some X-Session-Crash-Problems. But now I noticed, that I can't use the touchpad anymore.

I'm running Touchpad-Indicator which has the "enable touchpad"-Option disabled. It also does not work when unplugging the USB-mouse like it did running 11.10.
I looked around a little but couldn't find any solution.

Thanks for your help!