Well, my dual G4/800 is silent again. Last night, I did a screen capture and got a kernel panic. Re-boot didn't bring the system back to operating. I figure it's the processor card. The fan behind the card has been unsteady lately. I just ordered a PowerLogix 1.6 GHz G4 (7447) card. The photo shows that it has a fan perched over the heatsink so that should take care of the fan problem as well. It'll be interesting to go back to a single processor, especially since the machine didn't start out that way. However, 800 + 800 doesn't equal 1600 in this case, so the 1.6 GHz G4 will most likely be faster in most everything. I suspect that it will be cooler and quieter, too. Anything I've missed perhaps? Within the past couple of weeks, I've been fighting with the SuperDrive and the hard drive. What else could happen?