My.Templates.CheckboxLabel problem

Hi. I am very new to ActiveWidgets so this might be something obvious that I have missed.

I am using the My.Templates.CheckboxLabel to put a checkbox in a grid where the data model contains a table that is populated from a Active.XML.Table.

However, when I click on any of the checkboxes I get a "Object doesn't support this property or method" javascript error on the this.setItemProperty("text", newValue);
line of the toggleValue() function (see below for the code for this function).
Any help would be greatly appreciated.

function toggleValue(){
var originalVal = this.getItemProperty("text");
alert("originalVal = "+originalVal);
var newValue = (originalVal == this.getCheckedProperty("true")) ? this.getCheckedProperty("false") : this.getCheckedProperty("true");
alert("newValue = "+newValue);
this.setItemProperty("text", newValue);
this.refresh();

}

Post Xml example, and your true & false labels also, maybe your data corrupts the XML

BJH

Did you find a solution as I'm having the same problem when using XML data? Any assistance would be appreciated.