A little long so I'll set up in bullet points:
Problem still remains...we have an approved ATP at $42,000 that doesn't expire until 11/15/11, a buyer that wants to buy at the approved price, a seller that needs to get out of her home, the buyer's offer meets all of the guidelines...and now we have this ridiculous value that we have to dispute. The buyer is FURIOUS!!!!!! Any advice on how to approach this situation?
Escalate! You need to get this stuff communicated to the right person. I would escalate as high up as neccessary both with the lender and the investor, at the same time. If you don't know who the investor is, google "fannie mae loan lookup" and "freddie mac loan lookup." Odds are good that it is one of those. If not, then call the customers service number at the bank and tell them you are just a financial advisor who is calling for some pertiant information to a mutual client, and ask them if they can telly ou who the investor is. Don't go into detail with them that you are doing a short sale tho.
Push hard to communicate the real story(There are only 3 numbers that anyone at the bank who has authority to make a decision cares about...1)what is the value 2)what is the offer amount, and 3)what is the bank's net.) If you can get these things communicated to the right person at Chase or with the investor, you should be able to wrap this bad boy up. Good luck!!!