I have a Motorola DCT 6416 III. Periodically I go through the following cycle with it.
1. I go to On Demand channel.
2. Hit Select Button, to get to menu. Nothing happens.
3. Hit it a few more times. Still no menu. Sometimes the words "Network Unavailable" appear, sometimes not. Sometimes the remote light on the DVR that shows you are pressing a button on the remote will remain constantly on, sometimes not.
4. At this point, the unit will no longer do anything... I can't change channels, etc. I have to power cycle.
I recently swapped boxes, but the problem persists. I have Cox Cable.