well get this. i may have fixed it. the heatsink was jammed with dirt and fur. i blew it out with compressed air. than nothing. computer dead! a few hours later i decided i'd just try starting it again and lo-and-behold it boots fine. weird. probably static discharge i'd guess. anyways it is 25c cooler on the die! if heat was the issue that certainly fixed it. however, even though that was needed i am afraid the culprit of the reboots is norton. like i said, there is no failure or halt in the log. it is a regular user log off/restart. i have other apps running and i am almost positive it is not the ups so if anything does it again it must be norton. since it is weeks apart. otherwise cleaning the hsf didn't hurt save for the no boot scare.
it is a high end machine,well built,plenty of psu juice. so, other than the heat it is not the hardware most likely. i'll just have to wait and see if it happens again.