Consider the following scenario: A solution contains three projects.
Project A (C#)
Project B (VB.NET)
Project C (VB.NET)

Project A references project C and so does Project B.
Project B also references Project A.

Now, when project A exposes a type of Project B and I attempt to use it from Project B I get the following compilation error (in project A):
Indirect reference is being made to assembly 'ProjectB', which contains 'ProjectB.MyClass'. Add a file reference to '.....\ProjectB.dll' to your project. This error could also be due to mixing a file reference with a project reference to assembly 'ProjectB. In this case, try replacing the file reference to 'ProjectB.dll' in project '1_App_Code' with a project reference to 'ProjectB'.

I tried to remove and reassign the references. Any ideas?