[flexcoders] How to force grid dataprovider to update when combobox editor option selected

[lagos_tout]

Hi, all.

I have the following code:

<mx:AdvancedDataGrid id="ticketsGridTop" height="115" width="150" 
allowDragSelection="false" 
        editable="true" draggableColumns="false" resizableColumns="false"
        headerRenderer="com.tailgate.platform.movietickets.HeaderRenderer"
        selectable="false" borderSides="top bottom" 
dataProvider="{model.availableItems}">
        <mx:columns>
                <mx:AdvancedDataGridColumn headerText="Ticket Type" 
dataField="name" editable="false" />
                <mx:AdvancedDataGridColumn id="quantityColumn" 
rendererIsEditor="true" 
                        editorDataField="selectedIndex" headerText="Ticket 
Quantity" 
                        editable="true" dataField="quantity">
                        <mx:itemRenderer>
                                <mx:Component>
                                        <mx:ComboBox width="20" 
dataProvider="[0,1,2,3,4,5,6,7,8,9,10]" />
                                </mx:Component>
                        </mx:itemRenderer>
                </mx:AdvancedDataGridColumn>    
        </mx:columns>
</mx:AdvancedDataGrid>

My problem is that the quantity field of my dataprovider doesn't update 
immediately after I select an option from the ComboBox.  
First I have to select, then I have to click a (second time) somewhere else, in 
order for the quantity field in the dataprovider's 
object to update. 

Any idea why this is, and how I can have the quantity field of the dataprovider 
update upon select, without the additional click?

Thanks much.

LT