Hi,

sorry for waking an old thread, but this might be useful for others struggling with dynamically filling text and what determines the proper filling order.

I had a similar problem as you described and xml nodes were populated with text programatically through InDesign API using C#. I was actually trying to adjust the node filling to match the visual order of the elements on the page (each dynamic text element was in its own frame) but then I found a way of handling it by ordering the layers using the layer pane to match the node order.
To conclude: as Frederick said, the visual order on the page layout doesn’t have much to do with node layout.
You actually have to match the layer order with the node order, but keep in mind that the layer order is in reverse sequence from XML nodes.

Hope this helps.

Cheers