My application needs to connect to two versions of SQL Server, 2005 and 2008. Because of the differences between the datetime data type on 2008 (datetime2) and 2005 the cached entity model (built by EF 4.1 in memory) is incompatible between the two if I go through a process to connect to an instance of 2008 and then try to connect to an instance of 2005. If I connect to 2005 and then to 2008 there are no problems. Before you start telling me to modify the SSDL file's ProviderManifestToken value remember that the POCO (code first) pattern does not use any EDMX file types in the project. All of that model data is generated at runtime by the entity framework and is not maintained in the project as EDMX (ssdl,csdl,msl) configuration files. So in essence what I need is a solution or work around to this problem so as not to have to redesign my model too much.