I called t-mobile and talked with a friendly person with blackberry technical support. He was not aware of the problem but he went and got a phone and he replicated this problem on his phone. (He asked if it came with case and when I said no, his reply was that sucks
)
As far as he knew, there was no immediate solution except to turn down the sensitivity of the track ball. He said he would forward something to RIM about this, though I don't know if that will do any good. I just wanted this issue recorded somewhere. More people should call t-mobile so that at least their tech people are aware of it.