Nothing's happened. I noticed it had stopped functioning in camera mode, but when I turned my phone on just now it moved a little bit, but wouldn't go up. Then suddenly it just stopped moving.
Cleaning you BB with canned air is the best way to keep lint and otherws oout of your trackball and keyboards and other ports. Give that a try, if doesn't work pull the rind off and check the trackball.
I had this same thing happen, I found the instructions for cleaning the track ball, and had to take it apart and clean it. Turned out there was a large piece of pocket lint under the ball hampering the rollers. Once I put it back together, it worked better than it did when it was brand new.
