sorry, I read again what I wrote, it's a little confuse.
there's a topic here :
http://xmoonproductions.org/viewtopic.php?f=27&t=3479&hilit=start.inilook at "method 2"
this start.ini script,
1st part :
unpack "./pack/pack_dungeon.bin" file to "./pack/pack_dungeon" folder
2nd part :
pack "./pack/pack_dungeon" folder to "./pack/pack_dungeon
2.bin" file
after unpacking, comment the unpack section immediatly (or go in your ./pack folder and rename unpacked folder), if not, you could overwrite all your modifications by launching filemaker again.