very odd audio problem

I'm having problems capturing 2 tapes shot on an FX1 in DV into FCP 6.0, the audio sounds weak and badly garbled (video is fine). But the crazy thing is, the audio sounds fine (good levels and quality)when the deck is hooked up to my HDTV using composite cables. At first I thought something might be wrong with my computer and/or FCP, but I captured from a different tape that was shot on my dvx and it captured perfect good audio. all my other tapes capture and play back fine, the only ones giving me trouble are these 2 shot on the FX1.

Steps of what happened:

1: attempted to capture 2 tapes shot on sony fx1 in DV(not HDV) by someone else into FCP 6.0.

2: notice video is fine, audio is badly garbled.

3: attempt to capture using both a second deck and a DVX, audio still captures messed up, however on the camera and deck speakers the audio sounds good.

4: hook up deck to HDTV with composite and notice audio sounds perfectly strong and clear.

5: attempt to capture a tape shot on my DVX into the same project using the same deck and cables as the FX1 tapes, audio is captured fine and sounds perfectly clear and strong.

6: double check project, capture, and sequence settings anyway, all show the usual DV 48KHz. I think this pretty much rules out a malfunction on the computer/software end.

7: notice that the tape sounds fine on the camera/deck speakers and TV speakers when using a composite(IOW analog) connection, so I hook a deck with composite cables into my DVX, DVX with fire wire into computer, set capture setting to non-controllable device, and attempt to capture that way. Still doesn't work.

8: thinking that the FX1 audio setting might have been messed up, I tried multiple combinations of capture settings on things like 32khz, 8 bit, you name it, still doesn't work.

I think I've pretty much narrowed it down to the tape or camera(FX1), what throws me is how the audio plays perfectly fine through an analog connection. I figured if the tape was bad or the camera messed up recording, the audio would be screwed up no matter what.

any ideas what could cause something so strange? I'm going to get the actual camera that the tapes were shot on, just to see if they'll somehow capture on it.


equipment:
mac book pro 2.6 ghz, 4 ghz RAM OSX 10.5.1, FCP 6.0