Canon HF S10 will not Import

I recently ordered a Canon HF S10. The first time I used it, I used my black MacBook (running 10.4.11) and iMovie '08 to transfer the files. Everything transfered fine. Later, I plugged the camera into my white iMac (running 10.5.7 and iMovie '08). When I did, I got the dull screen that tells you the computer must be restarted. When I restarted, it would no longer recognize my external hard drive, and gave me errors every time I tried to import from the HF S10.

I went through a process and was able to recover data from the hard drive onto another drive. I upgraded to iMovie '09. I initialized the memory on the camera several times. I still get an error when trying to transfer video. The archive option provides an error also.

I just grabbed my MacBook and plugged the camera into it. Bingo, the video transfers fine. Plug the camera back into the iMac, error. I have tried running the camera through the USB hub. I have tried running the camera through a USB port on the back of the iMac. I always get the same result.

Someone please help. I need to video something tomorrow, and will not be able to initialize the memory after I film that until I can get the movie onto my iMac.

What can I do to make it work?