Update - 

this afternoon Kris, Sarah, Gloria and I talked with Bob Detonte and Carol Consolver from SoCal.  They will provide Kris with information reconciling imbalance data.  They clarified that imbalance trading will be reflected immediately, thus lessening our exposure.  They agreed to several changes in the contract including procedures for posting of margin.  They agreed to consider our requests to increase imbalance tolerance from $2.5 million to $10 million, and to scale the requirement according to our credit rating.  We expect an answer on these latter issues later today or early tomorrow.  The first reaction was that $10 million may be a "little too rich".