If I render a partial from a view and pass a null value the base model type gets passed rather than the model / value I actually passed. This is counterintuitive and would force people to pepper their views with an extra 3rd parameter 99% of times. More detailed information in the SO question:

http://stackoverflow.com/questions/650393/asp-net-mvc-renderpartial-with-null-model-gets-passed-the-wrong-type

Please fix!!