Canon V50Hi-8 (8mm video recorder)chews tapes when i record

[terryn]

Hi the fault is it keeps chewing the tape after about 20-30 seconds of recording. I can play back what iv recorded with no problems the tapes im using are Sony Hi-8 HMP (Metal particle) if some one could tell me what mite be causing this i would be very grateful my email is [email protected] thanks.