Hmm, I thought that ext3 was virtually identical to ext2 but with journalling capabilities...which wouldn't be used when mounted ro. Have you tried mounting the ext3 partition ro as as ext2 parition?
Yeah, it seems to work fine to have everything mounted ro as ext2. The problem would be when the player remounts the drives to sync. At that point it looks like it just issues a remount without specifying type (i.e. something like mount /dev/hda4 /drive0 -o remount,rw) so the drive would then get mounted rw as ext2 which is what I we don't want.
-Mike