When theres strange things afoot with maya at uni the bes tthing to do is move the prefs folder out of the maya folder (in your docs) so ther eisnt one, then fire up maya again, it resets the prefs, and see if that works, if it does it means re-setting all your prefs but at least its working

If not you can just ciopy your prefs folder back over, and carry on scratching your head.

I've seen a similar thing but its a windows display setting so not much help on a mac