Missing type or namespace name
<p>This is an odd one, not one I've come across before. My project complies and runs fine if I have my classes in the root folder (Not in App_Code).</p>

<p>As soon as I move them into the App_Code folder then it will compile, but running it will bring up the old</p>

<pre>
CS0234: The type or namespace name 'Linq' does not exist in the namespace 'System.Data' (are you missing an assembly reference?)
</pre>

<p>I don't understand how moving the class(es) to the App_Code folder causes the whole thing to fall apart there?</p>

<p>Project target is .Net 4 on VWD 2010 Express</p>
