I have a 2007 2.2Ghz "Santa Rosa" MBP, which I've had quite the problems with for the past 3 (soon to be 4) years. Just starting this week, if I'm on Safari or iChat for instance, Mac OS X freezes and everything stops... yet the mouse cursor can still move. Very soon, the screen starts flashing black and white over the frozen screen (with Safari, iChat, or whatever still open and visible behind the intense flickering). This flickering only goes on for a few seconds though; but the system remains frozen, requiring a manual shut-down and reboot. Any ideas what's going on? It just started recently. Software has been completely up to date. Somehow I'm paranoid that the graphics card issue is coming back to haunt me again (I've had it replaced once already) but it doesn't seem like that's it. Would appreciate any thoughts. I was planning to ride this machine out and get a new MBP next summer, but the way things are looking I may have to speed up the replacement time.