I've got a 1.6 G5 and got the Panther upgrade. Fantastic!!!!! Ran into a problem with my HP 970 Cse. My wife tried printing a 13 page Word doc and every time she tried to print it would do about 3 pages and then freeze. Went into the print center and found that there was another print job that was on hold. Tried deleting this but it kept coming back. Then the printer froze, mouse froze, keyboard too. After this it started to get REALLLLLLY UGLY! Every fan in the G5 came on and I thougth that it was about to expolode. Well, obviously I couldn't do a force reboot using the screen. I tried rebooting with the power button but it was unresponsive too. Had to go to the manual and found that my last option was to unplug the G5 but with the possibility that I might lose all data or screw up the OS. Well, I thought about this and then called Apple. Meanwhile the G5 sounded like a Huey about ready to hover. The Apple rep said that the only option was to unplug so I did. Well, everything stopped and I waited a bit and plugged the power back in. The G5 booted normally and everything was ok. I went back to the print center and actually deleted the HP and then reinstalled it. Tried printing the Word doc again and the same thing (above) happened. Did the "un plug thing" and went back and deleted the printer. THEN I got smart and went to HP's download site and found that they indeed had a new driver for Panther. Downloaded it and installed and then reinstalled the printer. Everything works great now. Man what a load off my mind. Guess we have to look very carefully at all peripherals and see if their are new Panther drivers. Panther sure didn't like the old drivers for the HP. Lesson learned. Cheers