>I don't do much at all with XmlDocument, so I can't really tell you what the error message means without a little research. But is there any way you can figure out *what* changed in the XML? That might help pinpoint what the problem is.
I have found that one of the members entered a bad RSS link. So, in order to avoid logging an error in such circumstance, I simply included the LoadXml() method into a Try/Catch.