Tonight I was recording one program and I tried to change the channel to watch something. I got a message saying: Two tuners are in use. SELECT one of them to tune to 73 ESPNHD. Press EXIT to return to 4 KCNC. Then there is a black bar with the info of the program I am recording Without a Trace R HD 4 KCNC [Stop Recording] There isn't a second selection, so it knows I'm only recording one channel, yet it won't let me change the channel. Any thoughts on why?