I have an Ipod with around 7000 trax on it on an external hard drive. It was PC formatted. I recently bought a Mac and wanted to transfer my tunes. I used Ipod rip to put my tunes onto the Mac then reformatted my Ipod. It all loaded up fine apart from 100 tunes which would not because they were not authorised. I've tried deauthorising and authorising again to no avail. Any ideas?