probably no one has encountered this, my laptop has a similar problem with the built in button type mouse, but when I stop using it eventually it stops moving. I use an external mouse 90% of the time, because the button is hard on my finger anyway.
About 3 weeks ago the sound system was somehow getting feedback from the mouse, started buzzing everytime it moved, updated the sound driver and it went away...... Point being who would know or guess that? (havn't seen the mouse problem in a while too, so may have been related)