Hey all -
I don't know if this helps, but I was experiencing fast motion using an old Sony cam (DCR-TRV 520) with my iMac and found a solution. This was the first time I used this camera since I used it with my old eMac (with which it worked fine). I connected the two and the connection seemed shaky; when it captured video, it played back in fast motion.
Anyway, I have an external FireWire hard drive connected to the computer, and just for fun before I gave up completely, I connected the camera to the hard drive's open FireWire slot and opened iMovie. Presto! Everything imported flawlessly.
Hope this helps!
Scott