Message is a reserved word in XLang. Can you change the name of the element/attribute that backs this distinguished field to something else? If that does not work, you could always XPath to the element to read it and use it. Last if those two don't work, you could make this a promoted property where you are able to specify the name yourself.
Here is the list of reserved words. http://msdn.microsoft.com/en-us/library/aa547020.aspx