Chrome history bug maybe - doing PRG, and when navigating again to the same form - no history entry is added
Chrome is strict about using HTTP 303 See other while your application uses 302 Found for redirects. See a related chrome bug report here: http://code.google.com/p/chromium/issues/detail?id=2801
You can vote to fix ASP.Net MVC's RedirectToAction here: http://connect.microsoft.com/VisualStudio/feedback/details/706961/asp-net-mvc-controller-redirecttoaction-method-should-return-http-303-response