In order to most effectively manage audio Tracks, they must first be added to the Library.This is done automatically the first time the application is run.Our desktop sync application imports information from i Tunes using the i Tunes XML file.As long as the i Tunes XML file is up to date, the correct information should be imported.
There does not seem to be any rhyme or reason to this, the files are mp3s and m4vs, both purchased from i Tunes and imported from CDs, they are randomly scattered about the library, some albums are hit worse than others (3 or 4 songs go missing), some are not affected at all. EDIT: Some software details: Apple released a "fix" release I believe, 9.0.1. As Radolph Potter said, you didn't provide us with enough details of your pc configuration to be really able to help.
But seriously, apart from not giving more details, i Tunes losing files is a critical bug.
Losing i Tunes database isn't so critical because you can always rebuild, but personal files is another matter.
In this version of i Tunes, the folders with the Dutch name have been emptied and the songs have been copied to the folders with the English names.
However the i Tunes DB has not been updated accordingly, hence a number of songs with Unknown Album and practically all of the ones part of the Compilation went missing.
If you've added music to your i Tunes library by ripping a CD, or importing MP3 files then you'll probably have songs that need artwork.