[flexcoders] Flex Menu.createMenu on mouseDown issue

[method_air]

Attempting to create a flex Menu on 'mouseDown' is failing (but works using the 
'click' event):

private function createAndShow():void 
{
        var myMenu:Menu = Menu.createMenu(null, myMenuData, false);
            myMenu.show(10, 10);
                        }
                ]]>
        </mx:Script>
        
        
        
                <!-- Define a Button control to open the menu -->
                <s:Button mouseDown="createAndShow();"/>

Is there a workaround?

Thanks,

Philip