OMG! I am having the same exact problem, were you able to figure out what is causing it?
I have been searching forever trying to find the answer. I too am on a Mac, I'll have to see if it does the same thing on Windows, but it is soooooo annoying.
I even try and set the cursor to the edge of the screen so it's out of sight, and it always finds it's way back into the middle of the screen. GRRRRRRR!!!