The issue of temporary freezing of the screen has been reported already, but to my experience...I have discovered that I escape the freezings (always a minute or longer several times in a row) when I succeed to squeeze in a switch to Mouselook in the intermitting active moments between the freezings. In Mouselook I am perfectly fine so far. The moment I switch back to normal view, when I have bad luck I return in the series of freezings again. I also have observed that not only Macs suffer of this problem but also some of my XP friends. I hope this may contain some clue for a debug.....good luck (^_)