[flexcoders] Daily WTF..." Property top not found on mx.containers.HBox and there is no default value."

[Adrian Williams]

All,

   Ok,  so this is a bit infuriating...how is it that this is choking 
on my setting a "top" property from within a state for an HBox, which by 
all appearances is a very valid property for an HBox? All I've found on 
Google is everyone saying...'oh you need to get the latest flash 
plugin'...well, all that does is surpress the error message...there's a 
reason I'm using the Flash debugger...

   So, here is the code:

                  <mx:HBox width="98%" height="100%" 
horizontalCenter="0" top="10" bottom="10" id="groupedParts">
                       <mx:AdvancedDataGrid 
                              .
                              .
                              .

   Then in my state change, I need to change the relative position of 
the hbox to allow for an inserted line of text:

           <mx:SetProperty target="{groupedParts}" name="top" value="27"/>

   So when I run the app and change the state, it throws the error
ReferenceError: Error #1069: Property top not found on 
mx.containers.HBox and there is no default value.
   at 
mx.states::SetProperty/apply()[E:\dev\3.0.x\frameworks\projects\framework\src\mx\states\SetProperty.as:205]
.
.
.
  
   I would greatly appreciate any help anyone can provide into this 
very mysterious error...

Thanks,
Adrian