I have an MZ-NF610 that sometimes works wonderfully, but at other times, the recordings come out distorted. They sound as though I had stuck the audio cable into a microphone jack instead of a line-in jack, but of course, that's impossible because this model has no mic jack. When it happens, it is not because I have changed any settings. All I use it for is to record programs off of the radio. I can't figure out any reason why one recording would be fine and the next one would be horrible. It's not the discs, because it sometimes happens on a disc that just recorded fine. Anybody got any ideas?