My On Demand stops working pretty much every night. I get the error code VM-255, which tells me to unplug the box. This only resets it if I actually unplug the coax too. I have tried with two different sets of coax wires. It started, so I got a new converter box, and it continued. Comcast technicians then blamed me because I installed the new box. It seems to get confused once it's working occasionally, and quits again, but generally it just won't connect when I press On Demand. I have to unplug the coax every time I want to use it. The TV portion works fine. I have Standard definition, and slow non-Comcast internet service. Can anyone tell me if the problem is in Comcast's programming?