XL-1 firewire problem

The Canon XL-1 I'm using may be sending strange signals through the port (or electronics leading to it) that generate random beeps onto the audio track. These beeps are not present on the tape at all when recorded (I've checked on a deck, and through the RCAs on the actual camera. My only guess is that, as before it's a problem with the camera, or with the adaptec firewire card, but they say they've never heard of the problem.

Have you ever heard of this?

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