Thanks Roland. A power glitch might be possible as I have just switched to everything tied to a single power supply instead of having the mount on its own supply. It's a Powerwerx 30 amp supply so I thought it should handle the load; however, di/dt might be high enough to kick a large spike. I'll go back to the mount on its own supply in the future. In the meantime I may be able to find a PHD expert who can decode the log for me in case I have a software issue somewhere.