[flexcoders] Effects not playing when the trigger is defined on the "component definition"

[João]

Hello, 

By some reason, the following effect does not play:

<?xml version="1.0" encoding="utf-8"?>
<mx:Canvas xmlns:mx="http://www.adobe.com/2006/mxml";
rollOverEffect="myEffect">
        <mx:Button label="Test"/>
        <mx:Move id="myEffect" xBy="200"/>
</mx:Canvas>

But, if i change the code to:

<?xml version="1.0" encoding="utf-8"?>
<mx:Canvas xmlns:mx="http://www.adobe.com/2006/mxml";>
        <mx:Button label="Test" rollOverEffect="myEffect"/>
        <mx:Move id="myEffect" xBy="200"/>
</mx:Canvas>

It works just fine. 
For my specific application purposes, it would be important if I could
define the triggers like i did for the first example.
I've tried it with different components and effects, and the problem
is always there. Am i doing something wrong? How can i solve this?

Thanks, 

João Saleiro