It seems that whenever I try to take a full screenshot with either Grab or the keyboard shortcut my Unibody 15" MBP freezes up. Nothing operates. I can't click on anything but the cursor moves. The first time it happened I did a hard restart. Second time I tried it froze for a while and then it came back with the screenshot taken. Tried a third time and the freeze time was a bit less. At least it felt like it. Any idea what's going on or a way to fix? Thanks.