LINQtoSQL DataContext in Web Application problems

Hi,


I'm running Visual Web Developer 2010 Express on Windows XP and I'm having some trouble linking my DataContext to a control.
If I create a new "Web Site", add a new LINQ to SQL Class and add the database tables I want, then add a Control such as FormView and choose a new LINQ Data Source Type; my DataContext I created is visible in the list and all work OK.
If I do the same after creating a new "Web Application", my DataContext doesn't show up in the list, but if I go into my Code Behind I can access my DataContext through:
Dim db = new ForumDataContext()


Am I doing something wrong?
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