I know this is an old question, but have you got the Open Session In View module defined in your web.config file?
For IIS6, it should be something like:
<httpModules>
<!-- Other modules here -->
<add name="OpenSessionInView" type="Spring.Data.NHibernate.Support.OpenSessionInViewModule, Spring.Data.NHibernate21"/>
</httpModules>
Also, I may be wrong about this, but I think Open Session In View looks for a session factory named (you've guessed it) SessionFactory, & so you may also need to add this to web.config as well:
<appSettings>
<!-- Other App Settings -->
<add key="Spring.Data.NHibernate.Support.OpenSessionInViewModule.SessionFactoryObjectName" value="NHibernateSessionFactory"/>
</appSettings>
Simon Rice
2010-08-11 11:37:20