>>>I thought that the reference to MyFirstSolutionProject in MainWindowsProject is enough.<
>
>Nope, you need to add the reference to SolutionBaseFormsProject also ... no big deal though.
>

Thanks for the reply Bonnie. I ended up creating a helper class in the MyFirstSolutionProject so that I instantiate the FirstSolutionEditor from within the MyFirstSolutionProject. That way all I did was call the public method to do create it.