Wasted 5 minutes figuring out what was going wrong, maybe this will save someone else the effort!

When using RhinoCommons and CastleProject both from trunk there's a version conflict with NHibernate.

RhinoCommons has NHibernate Version 2.0.0.1001 (Including support for things like Multi criteria) ... and then the Castle Project is using NHibernate Version (1.2.0.4000) - this took me a little bit by surprise when I discovered that a monorail project I had was failing when attempting to databind properly when using the ARSmartDispatcherController... because I wasn't checking the binding errors collection, this was just failing silently... so a save would just load/save the existing record, without any binding.

Quick fix is just to use a  assembly binding redirect in the web.config: