iTunes is doing some weird things lately. I have a MPB 2011 and I have the latest iTunes. This morning I noticed that about 15gb's of my music was gone. I figured I deleted it by accident, so I just added it back from my external. This evening I went to listen to some music and found that some of the tracks had the ! next to them. I checked the file size in the finder and it was the same size, but when I added my files again there was no difference. I had to delete all of the files from iTunes and readd them in the library. Someone please help me. I can't keep doing this every time I want to listen to music.