Bundles can hide where things get loaded, but it's a valuable tool to make the application faster. There should be some C# code that specifies what gets loaded in each bundle. In MVC, it's in BundleConfig.cs in the App_Start folder. Start there. Next, look at the master page and finally the specific aspx file.

>Very difficult to figure out where the .js is being loaded. I commented everywhere where I think that .js maybe loaded and yet I still see the jquery-1.7.1 is loaded. So you maybe right, that it does get loaded twice. But where.