Has anyone set up the SQLServer sessionState with Mere Mortals .NET?

sessionState mode="SQLServer" sqlConnectionString="data source=(local);integrated security=SSPI;persist security info=False;"

I have placed the above line in the Web.config and the system crashes. I have setup the SQLServer with the appropriate permissions to the objects for the integrated security. I get past the MM login of my application. The next page appears fine. I enter the query information to get a set of records. Then the following error occurs:

The constructor to deserialize an object of type OakLeaf.MM.Main.Data.mmDataSet was not found.