(OT) Flaky USB Bus / printer

[paul.cour1-H+0wwilmMs3R7s880joybQ at public.gmane.org]

   Hello
   How would you check the functionality of a USB Bus / Controller?
   May we assume that if a typical USB device plugged in to
   a Win XP machine and seems to work, would that "probably"
   indicate that the USB interface (cable/controller) is "squeekie clean"?
   I have a new HP 6310 printer which doesn't work, but an earlier generation
   HP 3745 printer works fine (via USB).
   I've done a "reinstall" using the HP CD, of software / drivers, several
   times,
   without success.
   I downloaded the 6310 Driver via the Web without (printing) success.
   But hook up the old HP 3745 printer and create a sm file via NotePad editor,
   works (prints) fine.
   OBTW, took the 6310 back to Circuit City, got new item, followed
   procedure as above, without success???
   Is there a way to test USB functionality?
   Tried USB spigot on back of machine (different controller?) and get same
   results as
   USB spigot on front of machine???
   What other options do I now have?
   Is there other "Plug & Play" issues here, that I am not aware of?
   TIA
   paulc