This looks like a typo at http://docs.dhtmlx.com/doku.php?id=dhtmlxgrid:sub-grids
Later in XML the user will have the following code:
<rows>
<row id="some">
<cell>my_grid.xml</cell><cell>Data </cell><cell>Data </cell>
<row>
</rows>
And in my_data.html there will be the following lines:
Shouldn’t it be the same file at both places?