Ooooookay. Here's my problem. I keep all of my music on an external harddrive (because while I don't have massive quantities of music, I do have enough that I don't want it all on my main computer.) Problem is, thanks to some unknown thing, my mac partition has become corrupted. I can read it, thankfully, but I can't write it. So. I need to copy all the data off, reformat it, and then put it all back on. That's not my problem. My problem is the last time I had to do something like this... even though I rebuilt the library in iTunes, it completely wiped all the music saved on my iPod. This isn't a problem with my newer one (I just have to rebuild playlists, which are mostly genius-generated anyway) but my older 3G model is a pain... it's only an 8 GB, so my husband only syncs certain stuff. It's really tiresome to start over from scratch. Is there a way to keep this from happening? I'm not going to be changing any file structures, just moving it off, moving it back on. Why can't iTunes be smart enough to match identical files in different locations? Suggestions? Commiserations? Help?