[flexcoders] Comobox/DataGrid does not display data

[md_ars]

I have a Combobox and its dataprovide is an ArrayCollection(formType) which is 
being populate from XMLLIst(formXMLListB) as given below

 public function getForms(vForm:Object):void
                {
                formXMLListB = vForm.mtResult.tuples.item.tuple; // 
resultFormat=e4x
                var i:int = 0;
                  formType.removeAll();
              for(i=0; i<formXMLListB.length(); i++) {
                if (formXMLListB[i].item..stringValue[2] == 'FORM_TYPE'){
                        
formType.addItem({label:formXMLListB[i].item.stringValue[0].toString(),
                                                           
data:formXMLListB[i].item.stringValue[1].toString()
                                                          }
                                                         );
                }
              }

For some reason combobox is not populate eventhough I can see the data in 
dataprovider when run with debugger. The formType is [Bindable] variable.

<mx:ComboBox id="frmType" x="258" y="124" dataProvider="{formType}" 
labelField="label" width="281" /> 

It works fine when I define a dataprovider with static values.

Any suggestions?

Thanks
Arshad