I have the same problem. My HP6200 and Canon G2 have
worked fine under XP until recently when I installed a new
TV Tuner Card (Ledtek) which is in a PCI slot not related
at all (I think) to this USB problem. I have checked with
the XP help pages (there was a problem with USB that was
supposed to have been fixed in Service Pack 1 back in
September of last year). I followed all the steps
recommended about deleting the devices and latest XP
compatible software for the HP and Canon. But what I
really don't understand is why in the Scanner Camera
window of the Control panel, the "add hardware" line on
the left side doesn't respond to any clicks. What is the
show stopper here? SteviG