It depends on the terms of your offer that was accepted by the seller. It's a mistake to think that you do not have acceptance of an offer after the parties have reached an agreement when it's a short sale. The mutual acceptance date is the day the parties reached mutual agreement in writing (unless specified differently in the terms of the agreement). The agreement is conditional on the underlying lenders approval of the short sale proceeds but this lender is not the seller. Processing the buyer's side of the transaction should begin while the underlying lender is considering their approval. This is always an awkward situation for a buyer.
Don Dutton is totally right... once mutual acceptance has been reached most States require that Earnest Money be deposited fairly quick. In Washington State we open Escrow and deposit EM monies by the next business day after full mutual acceptance. The fact that this is a Short Sale and requires the Lien Holder or creditor to approve it is only a contingent part of the agreement between buyer and seller. There may be other contingent factors such as Inspection, Septic or Well inspections, Finance etc.... btw, Thanks for your personal email too.
-Don Leske II / Broker