OT - I don't think it is accurate to say that banks are "unwilling to lend" (the original topic of this thread) just because they are hesitant and careful before writing down assets (which is what a short sale is).
And note that the reason they are hesitant is several fold:
a) if they just accept it without substantial DD they aren't accounting for the current owner's willingness/ability to live up to their obligation to pay.
b) Worse, there is a history of such transactions lacking "arms length" between buyer and seller - aka fraud (e.g. since it is no skin off the seller's nose it is economically reasonable for him to bargain with the buyer in a way to disadvantage the bank).