InfoPath Dev

I want my form to store data about imported XML files in a repeating table. New information should go in a new row, but my code always replaces the existing row with the new data.

The schema is

     SAN (root)
     |-- my:ConstantVariables (group)
         |-- my:LassoCollections (group)
             |-- my:LassoCollection (repeating group)
                 |-- my:LassoFileName
                 |-- my:LassoBuildVersion

The data I want to store in LassoFileName and LassoBuildVersion is stored in strLassoXMLFile and strLassoXMLVersion.

The new XmlDocument "doc" I am making contains the following XML when the code is run:

     <my:LassoCollection xmlns:my="http://schemas.microsoft.com/office/infopath/2003/myXSD/2011-03-16T10:53:27">
         <my:LassoFileName>Lasso_Northern_Lakes_Colle_Collect_Output_20120420_115048_GMT-700.xml</my:LassoFileName>
         <my:LassoBuildVersion>4.1</my:LassoBuildVersion>
     </my:LassoCollection>

This looks correct to me.

Here is the code that doesn't work:

   XmlDocument doc = new XmlDocument();
   XmlNode group = doc.CreateElement("my:LassoCollection", NamespaceManager.LookupNamespace("my"));

   XmlNode fileField = doc.CreateElement("my:LassoFileName", NamespaceManager.LookupNamespace("my"));
   XmlNode fileNode = group.AppendChild(fileField);
   fileNode.InnerText = strLassoXMLFile;

   XmlNode versionField = doc.CreateElement("my:LassoBuildVersion", NamespaceManager.LookupNamespace("my"));
   XmlNode versionNode = group.AppendChild(versionField);
   versionNode.InnerText = strLassoXMLVersion;

   doc.AppendChild(group);
   MainDataSource.CreateNavigator().SelectSingleNode("/SAN/my:ConstantVariables/my:LassoCollections", NamespaceManager).AppendChild(doc.DocumentElement.CreateNavigator());

What am I doing wrong here?

Paul

I've discovered my problem.  My code left an empty row at the beginning.  Once I deleted that empty row, future AppendChild operations added a new row at the bottom.

Paul