Here is a link to an article which may explain why some of these large banks can't seem to review a short sale offer in timely manner. (without threats from an attorney).
Bloomberg.com: News: "itigroup, Wells Fargo May Loan Less After Downgrades (Update3)
By Mark Pittman, Alan Katz and David Mildenberg"
I have suspected all along Wells and BofA are pains in the ass because they do not want to have to acknowlege how truly screw up their books are.
In my opinion the short sale process seems to be designed to let the air out of the market as slowly as possible. It is quite possible if short sales were easier, prices would be lower and the banks would all be upside down.