Firewire and DV camera prob... not sure why

Question

I have been using iMovie 4.x and FCE 2.0 for years to capture DV, and I have always always always connected the camera via firewire thru a firewire hub and have never had any problems... until now.
When launching iMovie or FCE and then connecting the camera, it detects the camera and I can control it (at first) with the program interface, but it will not capture, and it will not show the video supposedly being captured on the screen--I get a blank blue or black screen. If I try to stop the capture or the camera thru the iMovie/FCE interface, I get the spinning rainbow disk of death and I have to give the force quit command about 25 times or just turn the computer's power off because of the total system freeze.
Back in January I added an external LaCie 350GB firewire HD, and am using it to store my captured video, but that worked just fine in that configuration for months, and until last week, didn't cause any problems--I could still connect the camera via the hub with no problems or conflicts. I've unplugged everything and replugged everything in a different port configuration and that does nothing, makes no difference, and the same problems persist. The only time I can get the camera to be recognized and properly controlled is if I plug it directly into the computer and bypass the hub. It works, but I've never had to do that before. I thought it was a faulty hub, but my iPod connected thru the hub just fine, just like it always has, and in every firewire port on the hub so it isn't the hub.
I've read that there may have been some issues with Quicktime 7.1.1, a very recent upgrade, and I did a downgrade to 7.0.4 and then to 7.0.1 with Pacifist, but that didn't help either--the problem remained with both older versions of Quicktime.
I'm going to try resetting the PMU next, but I'm looking for other suggestions or to see if someone else has had a similar issue. Any help or suggestions would be most appreciated.
Flat Panel iMac G4 1GHz, 1GB RAM   Mac OS X (10.3.9)  

Answer 1

Even the voodoo GarageBand fix didn't work--a major bummer.
I've done other things too: cleared my user and system caches; deleted all the log files; ran disk repair permissions and UNIX scheduled maintenance; trashed iMovie preferences; unplugged the whole computer from everything, including power, and left it like that overnight, reconnected and restarted; booted to open firmware and reset the NVRAM; and tried every possible configuration of firewire devices with and without the hub. The only constant is that same 'ol can't-control-or-capture-from-my-camera-thru-the-hub problem.
I've been holding out on the PMU reset, but unless there are any other ways that I may want to approach the problem, that's what's coming next.