This is one of two units I have (HR10-250) and the problem started a month ago when the card was not being read. D* sent a new card and no problems until last nite. I was getting x745 message and when I removed the card and did a reboot (unplug and plug back in, after 30 seconds of course) I got no pix and then after 30 seconds both the power lite and the rec lite on the unit came on. Then after 1 minute the unit shut itself off. I tried this 4 times with D* and, you guessed it, #4 is on its way.