     //  firstButton
     //---------------------------------- 
     
-    [SkinPart(required="false")]
+    [SkinPart(required="false", type="mx.components.FxButton")]
     /**
      * A skin part that defines the first button.
      */

    //  middleButton
    //---------------------------------- 
    
    [SkinPart]
    /**
     * A skin part that defines the middle button(s).
     */

    //  lastButton
    //---------------------------------- 
    
    [SkinPart(required="false", type="mx.components.FxButton")]
    /**
     * A skin part that defines the last button.
     */
