I have and HR20-250 that was recently spontaneously rebooting. The hard drive passed quick and full tests. Reinstalled software. Now, the machine occasionally (? 1/wk) just completely shuts down on its own from standby, requiring unplugging and reboot. Everything seems normal when it reboots; recorded and scheduled programs still there, etc. Is this a sign that the hard drive is really bad despite passing tests, or an indication of power supply problems, or something else completely. Is there a way to figure this out before spending the money on a new drive or power supply? Could this be a power cord problem? Help would be greatly appreciated.