Dish Network DVR Upgrade

I recently got a Dish Network VIP612 DVR to replace my old 510 DVR. Unlike the 510, the 612 can record two shows at once (which is nice). The HD programs look as good as they do off my old antenna depending on what the program is.

However, I've had several problems with the unit. Sometimes playback is choppy when playing a recorded show, viewing photos makes the box reboot, and the over-the-air antenna hookup reads low signal even though there is actually more than enough.

I've already replaced the unit once and the second unit behaves the same way which makes me think that these are engineering flaws and not manufacturing flaws.

Update:
I recently connected the 612 to an LCD monitor using a HDMI cable with a DVI (DVI-D) adapter, and it looks great!