iTunes not recognizing iPod.

In the second grievance of the night against the latest iTunes, I've noticed that my iPod is no longer recognized by iTunes when I plug it in. It shows up on the desktop just fine, but not in my source column, even after unplugging, restarting iTunes, etc. The iPod is Windows-formatted, so this way I can use it with both my Mac and PC. I considered this as a reason for not being recognized, but it's been working fine this way for as long as I can remember.
What's the problem here? -thanks