Nintendo DS -Zelda Phantom Hourgl?

I think there is some kind of Glitch --HELP ME!!! I am in the Temple of the Ocean King (Third Visit) and I'm on B2 looking for the key that Link is supposed to get with the boomerang to open the door to get to B3... I have the game book for the walk through, and for some reason the key isn't there... The key was on the first floor allowing me to advance to B2, but there is NO KEY on this floor (and now I am stuck, because I cannot go any further until I find this key!!! PLEASE HELP, I would like to beat this game and wondering if anyone else got past this point and have pointers... Or if they experienced this before... Please respond... Thanks sooooo much! :)