FCP Capturing out of sync

Hi,

I'm having a strange problem with FCP (6.0.6)

Whenever i try to capture a tape (Mini DV) of an interview it seams to push the sound out of sync when I go to play it back. It's out of sync by about 6 seconds by the time it gets to the end of the 40 mins of footage...

Let me run through my set up so hopefully it will help narrow down the problem. I'm capturing on a PD-170 on to a Mac Pro. FCP is set up to be a DV PAL timeline. I have checked that the source footage was recorded in DV and that the audio sample rate 48kHz. I have tried capturing the tape 3 times, with restarts in between attempts as well as after repairing permissions. When I listen to the audio through the camera, it appears in sync all the way through. I have recently updated to Snow leopard. However, this was also happening when I tried to capture it in Leopard.

Any ideas would be much appreciated!