As discussed previously (
http://mvccontrib.codeplex.com/workitem/7191) there are a few places left where T4MVC inappropriately uses RouteValueCollection to convert an anonymous object to HTML attributes.
I've created diffs that can be applied to make the changes to 2.8.1. As I'm not used to working with diffs or what format you need them in, I've included all patch formats supported by Beyond Compare.
Btw, did you know that you can shave 7kb off the size of T4MVC simply by using tab indentation?