Problems still with AVM MC1 B

[hankbank]

I am still having periodic communication problems with the AVM MC1 B. I had to power cycle the unit for it to reset tonight. If I have the navigator on the screen by manually setting my receiver to the appropriate input to show the navigator, I can see the C4 screen and move between the potential options (video, tv, etc), but I cannot get the units to turn off, or switch between inputs. If it is on dvd, for example, I cannot get the controller to respond to the push of the red C4 button. Can anyone provide any suggestions?

Thanks