Comment 19 for bug 375905

I was plagued by this problem for a long time (probably since 9.04), until I got fed up, opened my laptop and disconnected its touchpad permanently (I prefer a mouse anyway). That fixed the problem for me, but this is not something I'd recommend others to do, especially since there's often a switch or a BIOS setting to disable a touchpad.

Apparently the touchpad was producing random click events (even without touching it at all), or so Ubuntu thought, and my guess is that those frequent extra clicks often caused control objects to become stuck. The few times I booted into Windows I had no problems with the touchpad, so maybe the Windows Synaptics driver has a filtration mechanism or sensitivity control of some sort.