In one of my main data integration test harnesses I create and use Fluent NHibernate's SingleConnectionSessionSourceForSQLiteInMemoryTesting, to get a fresh session for each test. After each test, I close the connection, session, and session factory, and throw out the nested StructureMap container they came from. This works for almost any simple data integration test I can think, including ones that utilize Fluent NHib's PersistenceSpecification object. When I test the application's lengthy database bootstrapping process, which creates and saves thousands of domain objects, I start seeing issues. It's not that the setup and tear down fails, in fact, the test successfully bootstraps the in-memory database as the application would bootstrap the real database in the production environment. The problem occurs when the database bootstrapping occurs a second time on a new in-memory database, with a new session and session factory. The error is: NHibernate.StaleStateException : Unexpected row count: 0; expected: 1 The row count is indeed Unexpected, the row that the application under test is looking for should be in the session. You see, it's not that any data from the last integration test is sticking around, it's that for some reason the session just stops working mid-database-boostrap. And I've looked everywhere for a place I might be holding on to an old session and I can't find one. I've searched through the code for static singleton objects, but there are none anywhere near the code in question. I have a couple StructureMap InstanceScope singleton's but they are getting thrown out with each nested container that is lost after every test teardown. I've tried every possible variation on disposing and closing every object involved with each test teardown and it still fails on this lengthy database bootstrap. But non-bootstrap related database tests appear to work fine. I'm starting to run out of options and may have to surrender lengthy database integration tests in favor of WatiN-based acceptance tests. Can anyone give me any clue about how I can figure out why some of my SingleConnectionSessionSourceForSQLiteInMemoryTesting aren't repeatable? Any advice at all, about how to make an NHibernate SqlLite database integration test harness repeatable?