For months sometimes when I record a show part way through the picture goes black. I still get the audio. When I try to fast forward sometimes it sticks and won't, sometimes it will go forward, but very, very slowly even at 4x fast forward. It sometimes will not rewind. Some shows it will only play from half way through on out, but will not start at the beginning for any reason. This happens about once a month. Is this a receiver going bad?