Reference DLLs not loading in Visual Studio 2010

Question

I\'m working on a C# 4.0 project in VS2010 and needed to use some older DLLs containing controls that were created in C# 3.5 on VS2008. When I first add the DLLs to the ref

Answer 1

Turns out that it was something to do with VS2010 defaulting to the .NET 4 client profile, as soon as I changed it to the regular profile it built fine. There's a day wasted...