My touchpad stops working accidentally, what can be the problem? only rebooting helps.
In 11.10 there was a problem with the daemon which disabled the touchpad when typing. I think this should have been resolved and certainly isn't a problem in 12.04.
In general though, including for 12.04, there are problems with the touchpad and trackpoint misbehaving on Thinkpads in recent years. There are a few workarounds.
One is to add the
... and reboot. This makes the serial driver responsible for the trackpoints more inclined to reset itself, and seems to improve reliability.
If you have problems with the trackpoint disappearing after suspend, then the psmouse-suspend-modules package from ppa:jamesf/lenovofixes will make the system reload the relevant driver after suspend, which resolves a few issues. i.e.: