Issue with DHTMLXGrid cellType=ed[=sum]

I have an issue with dhtmlxtreegrid feature "Calculate sum of children values automaticaly with [=sum] "

I am not able to get sum of child nodes at parent node levels,rather I am getting [=sum] written in parent cell, inspite of sum of numeric values from children,
I am using grid.parse(object) method to load grid xml, but if I use grid.loadXml(“filepath”) the same thing works, My columns are created within the object passed to parse method. I am not explicitly setting coltypes by grid.setColTypes(…). I have included dhtmlxgrid_math.js in my path. Please suggest some solution.

Unfortunately the issue cannot be reconstructed locally.
parse method works well for math in treeGrid. If issue still occurs - please open ticket at support@dhtmlx.com and provide a complete demo.