Originally Posted by Dubdub
Doubt if an OS update will fix it. Sounds to me like the user got it wet or dropped it.
That was my first thought. But it was definitely not working, even after numerous battery pulls, and it worked immediatley and flawlessly after the OS upgrade, so the OS upgrade somehow got it going again (for how long, I don't now).
Is it possible that some kind of mechanical/electrical fault can cause some kind of locking of the trackpad that can only be unlocked with drastic action like an OS upgrade?
It would have been interesting to see if reactivation fixed it.