The problem is that you need intercept and rewrite everything in xhtmlstring. I am guessing that you are trying todo somethig like @Model.MainBody directly into your view. That will work for most cases. But when you have links or you have for instance a block inside and XhtmlString property you will need to use the Html.PropertyFor. If you are not using that helper you will get the behavior you have at the moment sadly. :/