Itunes ?

Hi, I am sure you've found your. Answer by now, but if not here it goes. I made the same upgrade to my Mac mini which has made it finicky when it comes to external hard drives, I myself use the apple time capsule as my hard drive and after the upgrade the Mac mini no longer recoginized the files. What I did was delete all the files and redown loaded them again. Don't delete them in the trash, delete them off the Mac mini, and then reload the library again... Simple step... Hope this helps...

I ended up taking it to the Mac Authority for help. It was going to be hundreds of dollars for them to do the work. He said why don't you just copy files form old HD { format problems} to the new HD.{ properly formatted}. I did this, then created a new library and told itunes to use it as my new library location. Then i deleted all the music i had inadvertanly stored on my mini.
I tried to reformat my old HD but i think it is fried. I need to get a backup and run superduper. Thanks to all that helped on this thread. I learned a lot.

Thanks very much for letting us know how things turned out, Streetdaddy. Your plan sounds excellent. Best of luck!