My Dual 1.8ghz G5 locks up all the time, and it's getting progressively worse...Lately, I've been having to shut off the computer by holding in the power button at least once a day, then restarting. It's 7am here right now, and I've already restarted the machine twice. I'm not sure what's causing it. I've done a full OS reinstall. I've done permission repairs. It'll lock up at random. It locked up when I tried to turn the iTunes visualizer on this morning (twice). It locks up sometimes when I use my mouse's scroll wheel in Safari. It locks up sometimes when I show "All Windows" with Expose'. I don't have anything third-party in the machine. The RAM is from Apple. No PCI cards installed. Time to call AppleCare?