iMovie import firewire problem

[stevol]

Help! New iMac 24", 2.8. Firewire 800 has two drives attached, daisy-chained to another -- one is for video capturing / scratch disk, other is for time machine drive. The Firewire 400 port is used for my Canon camcorder. My plan seemed to me a good one. However, when I first connected my camcorder, my time machine drive seemed to unexpectedly "eject" itself, and a warning message appeared basically saying I did not eject it properly. Furthermore, and most disturbing, is that iMovie 08 gave me a "communication error" message and I could not import video no matter what I did. It did detect my camcorder and did seem to communicate enough to make the camcorder play video on its own lcd, but no video actually transferred to the Mac. I tried iMovie 06 and with some luck it seemed to work. That firewire port (400) has worked recently with a different hard drive. Interestingly, when I disconnected both of my 800 drives, the import actually worked in iMovie 08! Yet I need one of those drives as my scratch disk! What gives! Help! If it makes a difference, my time machine drive is actually a 400 speed drive daisy-chained to the back of an 800 drive which in turn is connected to my 800 port. Thanks in advance. Frustrated to say the least.