Hmmm... it seems it's definitely got something do do with the installation of the new motherboard and re-installation of Windows 7. As claimed here. The old installation of windows is gone, and so are my iTunes Library.xml and iTunes Library.itl files. So I guess I'll have to erase the iPod after all. Darn.

Why oh why can't iTunes simply create it's iTunes libraty from the files it finds on the iPod itself? The Empeg was able to do that more than 10 years ago!