USB Root Hubs - Can't clear code 41

I plugged a Korg Nanokey into one of the four USB ports on my Dell Inspiron
E1505. Windows recognized it (dong-DING), then a few seconds later the
NanoKey, my graphics tablet and two external drives all went bye-bye
(dong-dong-dong).

In the Device Manager, all the USB Root Hubs are malfunctioned with an error
41 (drivers working, but hardware not). All of the fixes I've found on the
Web --uninstalling/reinstalling the root hubs, reinstalling drivers, running
Add New Hardware, last good configuration, etc. -- fail to fix.
Doubleplusunpleased.

I don't think that there was a power issue, because these are all integrated
ports, only one drive and the graphics tablet ran off USB power, and the USB
chipset has since passed a bootup diagnostic. Also, the peripherals
(EXCLUDING the NanoKey) are getting power during bootup, and are even
recognized for a moment before being shut down again. Windows just can't
"see" anything plugged into any of the USB ports.

Before I take the NanoKey back to the store and insert it into the salesman,
has anyone had this problem? More importantly, has anyone *fixed* this
problem? Again, I've gone through all the usual steps of uninstalling and
then reinstalling. What do you do when none of that works?