This is just me documenting a particularly weird behaviour of ASP.NET MVC.  Usually, it doesn't matter, but if you used your own controller factory, like with MvcContrib, it's a pain to diagnose.  Basically, if you re-use a controller, the ModelBindingContext's values are cached.  This is, to say the least, freaky, especially since you can see that the url has changed.  So, you fire up one page, move to another id and get back the first page.  In short, register controllers as transient explicitly.  If you're wondering how I found this out, consider that AllTypes in Castle Windsor registers services as...

If you're trying to use MVC incrementally on an existing project, this can be a bit of pain.  There must be some way of way of getting the routing logic to redirect itself, but in practice the following does the trick (assuming you're using the standard routing). public class HomeController : Controller { public ActionResult Index() { return new RedirectResult("~/Default.aspx"); } } Technorati...