This is a first for me. I've had a brand new Mac Pro for 2 weeks. Twice now I've been just getting started and I've gotten the gray screen shade that descends upon my monitor with the message (in 4 different languages) that says "You need to restart your computer. Hold down the Power button for several seconds or press the Restart button." I typically am running the same apps, so I haven't been able to isolate it that way, plus it's only happened twice. In fact, after the restart, I fired up the same apps all over again (Quicken, TurboTax, Entourage, iTunes, Safari). Here's the kicker: I used to do all of the same things 3 weeks ago on a single proc 1 GHZ G4 with only 2 GB of RAM. Environment is as follows: OS 10.5.1 (Leopard), 4 GB RAM, (2) 2.8 GHz Quad-Core Intel Xeon. Anyone seen anything like this or have any clues?