I had put an offer to buy a short sale home since feburary 2009 How long it takes to get short sale approved ?

Its been already about 7 months since I have made an offer to buy a house in short sale The selling agent keep saying the lenders are taking time , they dont update me of any status . I have an exclusive buyers contract and Iam the higgest bidder ? I there any way I can push this sale faster or send any kind of court or lawer notice to lenders to tell them to make decesion on the property ? how much time I have to wait ?: is there a limit to wait for answer ?
the house is in california
I still want the house the original price came in the market was 325k i offered 310k
can i send any lawyer notice to bank to speed up process or any other way to speed up process ?