Multibridge Pro, FCP 6 - Capture Audio Sync Issues

Okay, the frustration level has hit the roof. After several calls to BMD and still no resolution, I am going a bit mad. We have a MacPro 2.8 with 8 gig of ram & 1T raid with the latest OSX, FCP & BMD drivers. For the record, 10.5.4 OS, Quicktime is 7.5, FCP 6.0.4 & BMD 6.7. There is nothing else installed as this is all super fresh to eliminate problems. Whenever we capture analog audio/video the sync is off and continues to drift ever more off over long captures on playback. If we switch the audio playback to the Mac, the sync improves, but is still off. The same problem occurs when we test with BMD Decklink software for capture and playback.

Is anyone else seeing these issues with the latest OS releases? It's nearly impossible to get older software installs from Apple so I'm at the mercy of the latest releases.

And just to make things even more odd. We pulled out an old Sony DVMC convertor which is just a simple firewire/analog convertor, nothing fancy, and captured with DV compression. Playback, even through the Multibridge Pro is perfectly in sync.

BMD is telling me there is no problems with driver conflicts that it must be a problem in my system, but had no suggestions as to where to look. There are willing to test my Multibridge Pro if I return it, but that only eliminates the hardware factor. I spoke with the tech support dept for the retailer we purchased from and he laughed and basically told me BSD is cheap crap and I should have bought Kona. Well... That isn't going to help me now.

Suggestions?

Matt @ Post Pro