I have an IIS7.5 web-site, on Windows Server 2008, with an ASP.NET MVC2 web-site deployed to it. The website was built in Visual Studio 2008, targeting .NET 3.5, and IIS 5.1
Checkout if KB 2023146 applies to your scenario. Also try requesting directly a controller action: /yoursitename/home/index
I had this problem when running my MVC4 site with an app pool set to ASP.NET 4.0 and the Classic pipeline, even though the extension handlers were set in my web.config and were showing correctly in IIS. The site worked in Integrated Pipeline so I knew it was a configuration issue, but I couldn't nail it down. I finally found that ASP.NET 4 was disabled for the server in the ISAPI and CGI Restrictions settings. I enabled ASP.NET 4.0 and it worked.