This post from Chazm solved it: simple really!! Thanks for your help...
Didn't read the whole post but I am assuming you can't scroll either up or down.
1. Turn phone off (or you might access something unwanted)
2. Push real hard on the track ball
3. While pushing in, scroll up and down.
4. Do it a couple of times and it should be fixed.
Again, I read this post real quick so you might have another prob.