Good question. Is there is more than one loan on the property? Are there tax liens, HOA liens, etc.? An additional loan or liens can lengthen the process. Also, is the listing agent handling the short sale or do they employ a professional negotiator to help navigate the short sale process? If the listing agent is handling it, are they experienced in handling short sales? There are many pieces to a short sale puzzle.
Since each short sale is different, one may me be approved within a few weeks, while another can take many months. It just depends on what is involved. Hopefully, your patience will pay off and you will get a great house at a great price!
Best of Luck,