need some help: Rekordbox is not marking missing files and relocate not working

Hi,

My database is ~2000 tracks.

i noticed yesterday when playing that a few of my playlists were empty on both my USB sticks, which i had sync'ed before taking them to the club to play.

i realized I did move a few folders that night, but i hadn't gotten any file missing warning.

when selecting all files in my collection and doing File -> Display All mising files i get an "all files exist" message.

However when I click one of the files that should have been on the USB device in my local computer collection, i get an error saying "file not found", but it doesn't get marked with the yellow triangle and the "relocate" option is missing from the menu!

I've tried with the backup DB and I get the same problem.

Then I started a fresh, empty DB, added a couple of files and them moved them elsewhere in my drive, and the relocate feature was already working... So I've nailed it down to a DB problem.

I can't even consider redoing the database from scratch, with all playlists, cue points etc... 

Is there a way of repairing / recovering my old DB? Remember, there are no errors being reported at all...

Running Mac OS X 10.8.3 / MB Air 2012

Rekordbox version 2.0.3