My Silverlight 4 app is hosted in ASP.NET MVC 2 web application. It works fine when I browse with Internet Explorer 8. However Google Chrome (version 5) cannot find ASP.NET
This doesn't directly answer your question, but I would suggest you try Fiddler, and look at the actual request that is being sent by the browser. Compare the differences and try to figure out what's going wrong (you can use the "Request Builder" tab in Fiddler to eh-hm, fiddle with the parameters).