There are many offers out there on Short Sales! Which ones are qualified for the tax credit? The Tax credit says that a buyer must be "under contract" by April 30, and closed by the June 30th.
If you made an offer on a short sale and the seller accepted your offer in primary or first position anytime before April 30, you are safe! You are under contract for purposes of the tax credit. If you are in a back up position you are not under contract.
If you are not under contract, I would try to find out what you can do to get in first position if you have an offer in, or I would identify a property that is available and get under contract.
Bank approval, price approval, and third party approval are just contingencies, just like the due diligence and financing/appraisal conditions are. The contract is between the buyer and seller and the bank is not party to the contract. No back up offer, whether its on a short sale or not would be considered to be under contract. A back up offer is just a reserved option to become the primary or first position offer which makes you under contract or pending.
It is not too late to find a home for the tax credit! If you or someone you know needs help, give me a call or email. I would be happy to follow up and help them!