In our MVC application, I'm trying to return XML from a controller using either AjaxReturn or AjaxStoreReturn. However, the ext:Store can't seem to process the returned xml. I've changed the Reader type of the ext:Store to JsonReader and XmlReader with the same result. Do I need to convert the xml to something before sending it back to the store?

Note that the xml is generated dynamically and is formatted like the plant.xml sample with the transformation plant.xsl.