Cointainer-Rendering Problem, but with the addition.....

After reading the API again, I've tried the following:

First Example:

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SwingEngine swix = new SwingEngine("xml/animation1.xml");
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if (Combo Item...............){
center_panel.invalidate();
center_panel.removeALL();
center_panel.add(swix.find("anim1")); /*anim1 is the id from the button 
<button id="anim1" icon="....." />*/
center_panel.validate();
}


#################################

Second Example:
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SwingEngine swix = new SwingEngine();
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if (Combo Item...............){
swix.getIdMap().clear()
center_panel.invalidate();
center_panel.removeALL();
swix.insert("xml/anim1.xml", center_panel);
/*the first tag in the xml file is a "dummy tag", therefore the panel tag 
should be insert in my existing panel.
<dummy>
<panel>
<button id="anim1" />
<button id="anim2" />
</panel>
</dummy>*/
center_panel.validate();
}


Both Sample, didn't solve my problem.

After the Combo Choice, all components were removed from the center_panel, but 
there aren't new components, that should be there after the add(..), 
swix.insert(...).

The find(String id) method returns "null", but the id/Button exists in the xml 
File.

What's wrong in the above samples?

Regards
Erik