We have an MVC 3 site that was running happily in dev, but when the client asked us to install it on their server (Windows 2008 SP2 (NOT R2), IIS 7.0), it wouldn't work; every View returned a 404.
We had just installed MVC 3 and ASP.NET 4, so we went though all the usual suspects:
- Integrated pipeline
- runAllManagedModulesForAllRequests in system.webserver
Eventually a random comment on some forum led us to the KB980368 Hotfix. That solved the problem!