We used a standard def tv without any bugs whatsoever. Using the same DVR and after connecting a new Sony Bravia to the unit there isn't a day where the system doesn't lockup or reboot. The problem is intermittent. As an experienced software engineer it seems likely the problem is caused by unhandled software exceptions in the hi-def specific code. However, it is possible the unit has a hardware problem but that seems unlikely. Also, after switching to hi-def, depending on the temperature of the room and whether the ambient sensor is enabled, the Bravia spews out quite a bit of IR noise which sometimes confuses the u-verse DVR (like sometimes spontaneously going mute.) It might be the intermittent reboots and lockups are caused by an overload of noisy IR signals from the LCD tv where on occasion some of the noise looks like a valid but confusing remote transmission. The problem is so bad, that unless it is resolved I will have to change services.