I suspect they want to make some monthly quota- or get you closed before they lower prices/add incentives. See if they will negotiate some sweetener if you do it by the end of the month.
In fact, the advice you are going to get here is probably to walk away, either using some loophole to get your deposit or screw the deposit. Even if your not ready to do that I suspect you have substantial leverage to improve your deal. Look closely into prices/incentives they are offering now vs. when you signed up.
If you are willing to say what project this is, I am sure you will get some much more valuable comments from the board.
