My new Mac Pro has the common symptom for such machines of rebooting when you wake it from sleep. I have the original hard disk, with nothing but a user added, and that works fine -- goes to sleep and wakes up as it should. But my other disk, which I made by installing the OS from the disks that came with the computer and then importing the users and apps from my old mac via firewire has the problem. This means that the sleep issue is software-related. I've tried to figure out what is causing it, but can't. Does anyone have any idea what software component is causing this behavior? I do have a LOT of apps, etc. etc. from earlier machines.