Make sure that both sources are 48 kHz.
(looks like one is 44.1 and the other is 48 now)
What tapes were used in the camera (DV, Hi8, DigiBeta, etc) and what on the house mix (DAT, audiocassette), etc.
In other words. Were the sources running at the exact same speed AND samplerate while recording? Otherwise yoy’ll need some pitching.
Tell us more about the setup.
Rienk