Changed the DSR-11 to a Panasonic GS230 camcorder, and the problem goes away!
Must be something to do with FCP and the Sony deck, as the deck works perfectly under Adobe Premiere Pro on a Windows machine.
Unfortunately, I’ve had FCP forced on me at work, so I’ve got to use it, so I guess my employer will have to come up with some replacement hardware.
I like FCP6, although I’m still getting used to it, just a shame that the trouble free transition I was expecting with a Mac hasn’t occurred… Macs can be just as problematic as Windows it seems 🙁