I have had a problem with opening some songs to the greeting of missing audio file screen. When I do the search they aren't found. Parts of the song will play but where some audio was recorded there is a line in the track window where the audio used to be. I have started saving all my files as CWB thinking this may help but not sure. Could these audio files be getting removed by Media player or iTunes? I am stumped.

Are you using per-project folders?

CWB is not the way to go. Always save using CWP and per Project Audio Folders and always have at least 2 copies of every project on different hard drives. I have 3 copies and 1 is left off site incase of fire or theft.
 
That said, after you started saving them as CWB's , did you ever check to see if they opened correctly?
 
CJ

I don't know what per project folders are but the box for that is checked and how do you check if they opened correctly? My  thought using cwb that if the audio is stored with the song maybe they wouldn't get separated. I have been using cwp until this problem. I  just can't figure out where the files are. Thanks for any help.