Haven't heard of that one, not playing on mac myself. Several friends use Macs and are and are crashing/load slowly. I would suggest rebooting the machine and plugging the mouse into another USB slot. If its a wireless mouse try a wired one maybe its just the wireless mouse.
I know Apple is giving out OS Updates for free now (One release to the next) If your not on the most recent build of OSX it might be worth upgrading because it should be free.