Since upgrading from Lion to Mountain Lion GM I've found my mouse pointer disappearing about once a day. I'll be browsing in Safari when the pointer disappears. It's still active in some way as roll-over effects are active as I attempt to find the pointer by moving my finger around the trackpad. After 10-20 seconds or so it appears again. Safari is basically all I use on this machine (nothing else running) so the system isn't under much load. But because I only use Safari I couldn't say if the issue specific to that app or not. Any ideas? P.S Additionally I've had a flickering affect on the text for a download listed in the current downloads pop-up bubble. Not sure if that's related.