Does the seller pay the mortgage, taxes, utilities on a house with an offer waiting for bank approval? Once the bank approves and accept the short sale offer might there be additional charges if the seller has not been paying mortgage on a home where he no longer lives? If they accept my offer do they often come up with other charges left behind by the former owner?

Last year I attempted to purchase a house that was up for short sale. The owner accepted my offer but the bank denied the short sale. Now the owner has stopped making payments and we are trying the short sale again. I am willing to pay the appraised value for the home. What determines whether or not the bank will give the thumbs up or down on the short sale? Is there anything I can do as the buyer to help the process go through?