I'm a little confused to what model you have, trackwheel, 8100e...
If you have a trackball (the one in the center of the device 81xx,83xx,88xx) Problems with it can usually be freed up by doing the following:
Turn the device off (stops you from clicking on things while doing it)
Press Down hard on the trackball and roll it around in all directions while holding it down.
This usually frees up anything in it that is stopping it from working correctly.