Hi,
is it possible to set splitAt() after loading XML datas?
In your bestiary (http://www.dhtmlx.com/docs/products/docsExplorer/doc/dhtmlxxml/index.html) i see settings parameter but it doesn’t seem to work.
But if i call mygrid.split() in javascript script after grid.init() and before load it works. So you like do here: http://www.dhtmlx.com/docs/products/dhtmlxGrid/samples/09_frozen_columns/02_pro_split_multiline.html
And yes, dhtmlxgrid_splt.js is inserted. 
Carsten
the following combinations work well for us.
before the data is loaded
grid.init();
grid.splitAt(1);
grid.load(url);
after the data is loaded
grid.init();
grid.load(url,function(){
grid.splitAt(1);
});
If issue still occurs for you - please, provide with any kind of sample of your code.
I know that
grid.splitAt();
works in JavaScript but splitAt() doesn’t seem to work in XML as in your bestiary. 
I’ve 3 fix columns and additional unknown number of columns so i would decided on server side to split or not the grid.
Please, try to use the following solution:
...
<column type="ro" width="150" sort="na" id="last">column 3</column>
<afterInit>
<call command="splitAt">
<param>1</param>
</call>
</afterInit>
<row id="1">
...