I have my iPod formatted for Windows (FAT 32). Windows and my PowerBook have no trouble reading it. If you have it formatted for the Mac (HFS), Windows is not going recognize that format and will do funny things.
Also, if you are using iTunes on both your Mac and your PC be set iTunes not to update your iPod on connection so it won't touch the data on it.
Funny though, when I read your reply I decided to hook up my iPod to put some new music on it and I had my first kernal panic!
edited: for poor spelling