I'm having a periodic problem...occasionally my imac jumps to the previous page without my telling it to. For example: in safari, I've moved the Magic Mouse to the top left of the screen - but b4 I click the arrow to go back a page it does it on it's own. (Or once, Aperture 3 close on it's own when I moved the Magic Mouse to the top left area...but never clicked anything.) Any ideas what is going on?