I have a WPF Application using Fluent NHibernate 1.0 RTM and System.Data.SQLite 1.0.65 that works fine in .Net 3.5. When I try to upgrade it to .Net 4.0 everything compiles but I get a runtime error where the innermost exception is this: `The IDbCommand and IDbConnection implementation in the assembly System.Data.SQLite could not be found.` The only change made to the project was switching the Target Framework to 4.0.