I'm having a problem with writing nested xml data in a web application using

c# in asp. 



Here is the basic issue:



I have an existing xml file with nested elements, structure as follows: 

<a>

	<b>

		<c>

			<d1> data </d>

			<d2> data </d2>

		</c>

	</b>

</a>



 I can read it and display the nested data in a DataGrid just fine.  

When I add a new instance of one of the child <c> elements, containing

another set of <d> elements, it does not seem to be recognized as part of a

nested structure -- it gets placed at the end of the xml file as a child of

the outermost <a>element, not as a child of the <b> element.  I've tried

using both DataSets and XMLDataDocuments with the same result.  I've also

tried both an explicitly specified schema and letting the schema be implied

from the structure of the input xml.  



Does anyone know if there is a known problem with nested elements in xml

datasets in .net? Or in VisualStudio.net?  

I noticed that if I edit the xml file manually in Visual Studio, I also get

the same (erroneous) results.