XML Author does not always auto add the closing tag in code view.

Using the XML Author portion of Framemaker 12 (code view) and validating to a Navy IETM DTD. Occassionally when I open the xml file in Framemaker and add another element such as a para, when I type the closing > of the para opening tag Framemaker does not automatically insert the ending tag (</para>) and states "the element 'para' has invalid child element 'para'. If I manually add it, it removes the ending tag from the next para element below it and messes up the xml file. I have to undo or close without saving. Does anyone know why this would happen. The DTD has relative reference to a parent directory on win7 laptop. Sometimes it works fine and other times it does this quirky thing. Thanks.