T5: Mixin on Form does not work as expected

[Kristian Marinkovic]

hi,

i get an exception from the Form.cleanupRender method although
i have a Mixin attached that returns false on setupRender.

as i understand the documentation correctly the Form component
should never enter the cleanupRender method/event... 

can someone point me to my error?

i'm trying to short-circuit the form rendering when a certain state
occurs 

thanks
g,
kris

code:
page:
    @Component(parameters={"tracker=tracker","Editable.edit=display"}) 
    @MixinClasses(Editable.class)
    private Form orderForm;



Editable Mixin:
public class Editable {
 ...
 
@Parameter(defaultPrefix=TapestryConstants.PROP_BINDING_PREFIX,value="true")
    private boolean edit;

    boolean setupRender(MarkupWriter writer) {
        if(!edit)
            writer.write(value);
        return edit;
    }
}