I will check those out. I did use TechTool pro and it told me that the fans all operated at a proper speed. I did not notice if TechTool pro checked the temperature or not. Thanks again for the help!You could try one of the utilities that will display the various temps reported in your MacPro.
I use smcFanControl, but there's also Macs Fan Control - and a few others that I can't think of right now.
That can show you if the temps are spiking when you get your reboot. If the temps don't seem to change noticeably, and not really connected to the reboot, then it may simply be an issue with the power supply.