Index: apps/metadata/mp3.c
===================================================================
--- apps/metadata/mp3.c	(revision 19923)
+++ apps/metadata/mp3.c	(working copy)
@@ -407,7 +407,8 @@
         if (strcasecmp(tag, "http://musicbrainz.org") == 0)
         {
             /* Musicbrainz track IDs are always 36 chars long plus null */
-            value_len = 37;
+            /* add the length of the string http://musicbrainz.org */
+            value_len = 37 + 23;
 
             entry->mb_track_id = value;