Bad experience with iTunes

I plugged my iPod into the PC for the first time since installing iTunes 7.3, and I get this:


So I hit OK, click "Restore", and it resets my iPod to factory defaults.  The iPod reboots, and when it re-connects to iTunes, I get the same dialog.

Now what?  I can't get any music on my iPod.  :(

Update:  Turns out it was a drive letter conflict, not iTunes 7.3.  This article describes the problem, and this article has the solution.