I have had my Series 3 Tivo since last September and on Monday had my two cable cards installed. There were a few issues with Comcast getting them installed but they were working correctly with in a few hours of the tech leaving. Last night the Tivo button stopped working on the remote and then I even tried to use the Tivo button on the front of the unit itself and that did not work either. I was trying to make a network connection and my cable had came unplugged so I pulled the plug on the unit to restart it. The Tivo button was working fine after the restart. I also changed the batteries in my remote as well. All my channels were working last night. This morning I get up and the 161-4 error is showing and after messing around I have no channels but after a few miniutes they came back and all seems to be fine. Why did this happen? or should I not be concerned?