From the article in The New York Times, Company Stops Insuring Titles in Chase Foreclosures:

Mark P. Stopa, a lawyer in Florida who represents defaulting homeowners, said that if more title insurance firms began to shy away from insuring foreclosed properties, the entire housing market could suffer. The prices of foreclosures would plummet, because lenders will not issue a new mortgage without title insurance.

How many more shoes are there to drop about the collapse of the housing bubble?  Usually, after the second one drops, you stop waiting for another shoe.  This has got to be at least the third shoe.