title: TypeLoadException says 'no implementation', but it is implemented
body: <p>I've got a very weird bug on our test machine. The error is:</p>
  
  <p><code>System.TypeLoadException: Method 'SetShort' in type 'DummyItem' from assembly 'ActiveViewers (...)' does not have an implementation.</code></p>
  
  <p>I just can't understand why. <code>SetShort</code> is there in the <code>DummyItem</code> class, and I've even recompiled a version with writes to the event log just to make sure that it's not a deployment/versioning issue.  The weird thing is that the calling code doesn't even call the <code>SetShort</code> method.</p>