That's crummy! I am not sure why they signed the contract if they were not sure...they could have just as easily said, we'll take it home and think about it a bit and then if we decide it's a yes, we'll bring the contract and the deposit. Maybe they wanted to keep you on the back burner while looking into some other option? It't not you! It's just that for whatever reason, they were not the right family for you. Feel glad that they ducked out early...imagine if they had waited until September and all this time you are thinking that you have the spot filled? Take a deap breath and say TGIF!