I'm going to venture a guess that what might have happened is you changed the mode of recording. VCRs record in either short play, or long play, or even super long play. As the length of playtime goes up, the quality goes down, because for short play, a 6 hr tape will record only two, whereas a 12 hour tape will record four hours. More information is stored on the tape, so the quality of picture and sound increase, but a longer movie could be cut off. You can adjust the play-length with the sp/slp buttons on your remote control.