onTopSelectorClicked does not work in 2.5.1

The following code no longer works in 2.5.1. Image shows but not able to click. Worked in 2.0

obj1.setTopImage("excel");
obj1.onTopSelectorClicked = function(event, rowIndex){if (rowIndex==0) exportGrid(data);};
// enable row selectors
obj1.setSelectorVisible(true);
obj1.setSelectorText(function(i){return this.getRowPosition(i)+1});
obj1.setSelectorWidth(25);
obj1.setSelectorResizable(true);

The suggested code does not work. When calling the function, the rowIndex is showing "undefined".

obj1.onTopSelectorClicked = function(event, rowIndex){
alert(rowIndex);
event.cancelBubble = true;
event.returnValue = false;
};

>> the rowIndex is showing "undefined"

This is correct behavior for AW.UI.Grid. For AW.Grid.Extended rowIndex will be 0 (or 1, 2 ... in case of multiple header rows).