Trackpad gestures broken in Snow Leopard

At some point last week I realized, that I could not use the “Rotate” gesture on my MBP (e.g. in Preview). It was just gone. After some googling I figured that the Three- and Fourfinger gestures were broken, too. So what happend? Apparently no one really knows so far. There is only an Apple-Technician, who posted that weird hint at the Apple-Discussions-Board. But the good news is: It works!

All you need to do is to shutdown your machine and boot into single user mode by holding [cmd] + “s”
Once you made it to the root command line, you force a filesystem-check of your system disk by typing

fsck_hfs -f /dev/disk0s2
reboot

And afterwards everything should be in place again.
Astonishing.