recording sound, but getting "dropout" ..

Hello Folks

Trying to record into PC from cassette player. Done it before, no probs, whole symphonic movements, up to 15 mins. Now, I record a short 3 minute piece, but it seems corrupted about 1 minute into the piece, and plays really fast. Repeated attempts vary, but it's usually around 1 minute, then the music is fast and jerky. Symptom similar to drop-out in video files, but here it's just sound.

Also, though the piece is about 3 mins long, the digital timer in the wave editor shows just over 2 mins. Very odd.

Using Nero Wave Editor to record, and Avance97 is the soundmanager, all in Win2000.

Any pointers, folks ? All help gratefully received.

Thanks

Rob