It happened again the other day- I tried to manually add a few songs- I'm fairly sure they were in the mp3 format- it was trying to sync, but they could not be added on for some reason- that circle kept going round and round on the IPOD without stopping- I finally said screw it and I cut it off (hit the x)- lo and behold most of my songs were unplayable. Basically my 2800 songs disappeared. On the IPOD- the song had a red circle with the square in the middle, and when you try to play it- it skips over it to the next song that is available. Why does this happen? I read you should not interrupt a sync. Is this the result? I had no choice but to interrupt it. I had to sync my library again. I was able to get all songs back on. What did I do wrong in this case? I prefer manually adding songs. Thx.