New Camcorder - Sound Problems

On a recent visit to the US I purchased a JVC GR -DX37 Camcorder which uses Mini DV tape. All was well until returning to the UK and reviewing the tapes.

The Video is perfect however the sound more or less contantly (with a few exceptions) cuts out and back in again. I used two differnt brand of tape which were brand new (Sony and JVC) and both tapes have the same problem.

Using a blank part of one of the tapes I have attempted to recreate this in the comfort of my living room. However on this occasion the play back is perfectly?

Could this symptom have been caused by the X Ray machines at the airport? or is there something wrong with my new Camera... Any thoughts would be appreciated.

Regards,
Trevor.