>>In the non-working project what does Intellisense show after 'Shell.' ?
>
>It doesn't show anything.

After the period? Very strange. The snippet of code I posted shows the error that you are seeing and I cannot think of any other possible cause. But even if Shell was an empty class you should still be seeing the .Equals and .ReferenceEquals methods.
What does the compiler make of 'Dim s as Shell' at that point..