I am having the same problem, and also asked canon their opinion. (waiting)
I bypassed final cut altogether, and was just capturing video with qt pro. It seems that the output of the live camera is outputing 1080i HD through the firewire port, but not the VTR. Any tape shot in HD is playing back in SD. – When a firewire cable is plugged into my mac
In VTR mode, I open the signal setup menu, and adjust the playback STD option to “HD” but I noticed that if you keep that menu open it grays out as soon as you plug in a firewire cable. I’ve tried multiple cables, ports and even looped it out of my ext. HD.
macpro 2.66 dual, 7Gb ram, osx 10.5.6,