How to be sure that my MVC project is running on the correct version after upgrade to vs2010?

I just installed visual studio 2010 and upgraded my MVC project (which was running on MVC RC2 in visual studio 2008). visual studio 2010 updated every project file to target the framework 4.0. But the system.web.dll is pointing to

C:\Program Files (x86)\Microsoft ASP.NET\ASP.NET MVC 2\Assemblies\System.Web.Mvc.dll

in VS2010 object browser, I have every dll showing up in multiple versions as 开发者_运维百科expected (3.5.0.0 and 4.0.0.0) except for the System.Web.Mvc dll which doesn't show any version and points to the path I mentioned above.

Isn't this namespace point to the Framework folder like the System.Web namespace?

C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETFramework\v4.0\System.Web.dll

MVC 2 uses the same binary for .NET 3.5 and .NET 4.0.