We are trying to write an application that uses the NServiceBus library in a VB.NET environment. We've been stymied by errors similar to the following:

Reference required to assembly 'NServiceBus, Version=2.0.0.1071, Culture=neutral, PublicKeyToken=9fc386479f8a226c' containing the implemented interface 'NServiceBus.IMessageHandler`1'. Add one to your project.

Our project already includes references to NServiceBus.dll and NServiceBus.Core.dll from the same NServiceBus 2.0 RC2 distribution.

Steps to reproduce:

1. Create a new VB Class Library Project (.NET 3.5)
2. Add NServiceBus.dll and NServiceBus.Core.dll as References.

3. Put the following code in Class1.vb:

   Imports NServiceBus.Sagas.Impl
   Class Test
       Public Function Foo() As SagaMessageHandler
           Return Nothing
       End Function
   End Class
   

4. You should now see the compiler error mentioned above.

An identical project written in C# has no compile errors.

Any ideas about how to solve this problem? (And, yes, my preferred solution is switching to C#, but no, that's not an acceptable one at the moment.)