We've had some discussions in the past about USB devices going away.  I 
have a Dell desktop; as noted, those seem to be more -- I guess 
"sensitive" is the word...

I lost my mouse twice today; each time, I had to reboot.  The system 
notices when I disconnect the mouse; it does not notice if I reconnect 
it under those circumstances.  Is there some way to force a reset of 
the USB adapter so that it will notice the reconnects?

		--Prof. Steven M. Bellovin, http://www.cs.columbia.edu/~smb