Hello. All my purchased music in my library has worked in the past and was also on my Ipod. I had synced it a while ago and I noticed only some of the recently played songs only appeared on the Ipod. I went to sync it again and when I tried to play a song from my itunes library it warned me that "the song '.....' could not be used because the original file could not be found. You would like to locate it?" All the songs still show in the library, but none of them can be used/played. Any ideas?