You can simply turn off the updated missing metadata in settings and we won't go get metadata for your files.
Just so you understand the process after you have moved the database to the side. We walk the watched folders looking for music. We add the music and read the metadata out of the file headers. Once we have that metadata we lookup using the same metadata lookup engine WMP uses(WMIS)...to find out which albums these tracks match. Depending on the data in the header of these files, this is done by uniqueIDs that are in the file, by a Table Of Contents(TOC) from the CD it was ripped from, or those aren't available...simply the text(using algorithms to match similar text) of the metadata in the file(album name, album artist, track name, track number, track duration, etc).
When the data comes back we will fill in missing data, but don't overwrite existing data(unless you have changed the defualt by checking the overwrite existing metadata in settings). Also if you use our UI to change the metadata by hand, we mark that it was user edited, and write that change to the file's metadata.
The one peice that becomes troublesome is that in some cases users can have a uniqueID in a file from WMP...but that UniqueID isn't the correct ID for that track and results in very different track metadata coming back.
Zach Johnson
Zune Client Development Lead
.: This posting is provided as-is with no warranties, no rights :.