Clam Puzzle: Virtual Villagers 3 - I've rebuilt the statue, but still won't work!?

I've rebuilt the statue and placed a Master Builder, Tribal Chief and Master Scientist on the snapping clam. None of them can do it. The clam just slams shut when they approach it and the message says, "Your villager sees a clam snapping at its feet." There's gotta be something I can do to fix this; don't tell me I paid $20 for the game, invested all this time and am now totally hosed!