everything worked fine for me on my p3 ibm notebook, win xp pro, usb 1.1 - i did get a verify error on bank 3, and later reflashed it with the same bios and re-verified and it was fine - don't know if i was mulittasking, or maybe it was just a random bad write, but all in all worked fine for me.
i'd make sure the yellow and black connectors are SECURELY installed - took a bit of doing to get them in. also, consider trying different usb drivers for your ports - maybe you can find 1.1 drivers for the 2.0 ports so they'll fall back.
i did NOT use win2k compatability mode - i just slapped the software on my machine and ran with it.
hope this info helps....