I've been using my M Mouse successfully with my MacBook until recently when the Mouse Pointer no longer moves. The button does engage the dashboard and if I position the cursor using the MacBook trackpad, then the click function of the mouse does work. I have tried changing the batteries. It appears I am having a similar problem when I use a wired mouse. Just in case it's connected, I run Parallels and did recently upgrade Windows software. Any ideas? Thanks for any suggestions!