When I have a single playlist in the playlist directory and perform a playlist rescan entries are removed from the genre_track table during the rescan.

I am running this with the mysql database, and verifies the result with the following SQL statements:
select distinct tracks.id from tracks where tracks.ct='flc';
select distinct genre_track.track from genre_track;

The SQL statements results in the same number of row before the playlist rescan, but after the playlist rescan there are to few entries in the genre_track table. The problem is the same even if the playlist has not been modified since the last full rescan.

My library contains .flac files only and many of them contains several genres in the GENRE tag separated with ;.

The problem also exists in "6.2.2 (2006-01-07)", I have also checked it in "6.5 (2006-01-06)" but there the playlist rescan seems to take forever so I can't verify if it works or not in 6.5.