Export structured data with XMLPort

Hi everyone,

This might be a stupid question, but, we're having troubles, and seems to be too simple to have problems.

Is it possible to create an XMLport for sales shipment header, and its related lines?

This is the structure:


And properties for the sales shipment lines node:

I have created a function to export the XMl into a file, but I only get the header...

Am I doing anything wrong?

It's NAV 2009 by the way

Thank you all!