Ok i havent have any problems with itunes since i got my ipod 8 months ago, but ever since last updates to 7.3 my itunes have become unstable often crashing and often giving me error messages, now i tought it was only me so i tryed it on my kids computer and theirs also having similar issues, sometimes not reconising the ipod other times crashing. other times refusing to sync. just thought i share that in case is not an isolated case.
I had the same problem until i finally got fed up with it and uninstalled itunes and got a copy of anapod explorer. it doesn't have the jukebox functionality of itunes, but it is so much easier for putting music on the ipod. http://www.redchairsoftware.com/anapod/
Try running the iPod repair/restore utility, it's on Apple's website somewhere. Maybe your database got corrupted somehow
