Apparently comcast's motorola dvr box does not support DVI yet. That is what the code stands for. It can only disply dui or du1 on it's box. It stands for DVI. It means the dvr and tv cannot communicate. Eventually the DVR will freeze and the only way to reset it is to unplug it for 1 minute and plug it back in. The solution is easy, don't use an HDMI or DVI cable. I used one of the component cables (the ones with five wires, three for video, two for audio) and the dvr started working again. Make sure you actually unplug the DVI/HDMI cable from the box and tv.