Stalling when transferring large files to usb 2.0 drive

The drive is an Archos Jukebox Recorder 20GB. It is basically treated as any other external usb drive. It is detected and mounts fine under Knoppix. However when I transfer a large file such as a 600MB ISO image to the drive the transfer starts slowing down almost immediately and stalls somewhere around 100MB. If I wait several seconds it will start up again but then start slowing down and stalling again after another 100MB and this keeps repeating the process. The transfer speed itself is also very slow. Under other linux distros such as Redhat and Mandrake and MandrakeMove cd as well as windows 2000 this transfer takes about a minute. In Knoppix it takes 20-30 minutes maybe more. This also seems to be present on systems with a USB 1.1 interface. With USB 1.1 on other systems tranfers take around 10 minutes for a 600MB file and in Knoppix will take over 30 minutes. I have experienced this problem on every version of Knoppix I have every tried. First version I tried I think was released in May. I have also had this problem on three completely different systems.

homebuilt Athlon XP 2500 USB 2.0 ATI 8500 265MB RAM
Omnitech Pentium 4 2.66GHz USB 2.0 Intel video 512RAM
Omnitech Pentium 4 2.0GHz USB 1.1 Matrox 512RAM

I admit I have not tried the very latest Knoppix. I am still using November 14 release and did not try November 19 yet. I did not see any kernel or usb driver updates listsed in the changelog so I suspect the problem is still there. I also have not had the chance to experement with a different usb drive. Any ideas? Anyone else experience similar problems with external hard drives (not flash) Anything I could try? Is there anything like hdparm but for usb drives? Is there some setting I am missing that I can change?

Thanks,
Ken