Problem with addInstance

Hello

I am quiet new to the LiveCycle Designer. I've created simple form just to check, how instanceManager.addInstance(1) method works. Nonetheless, when I press Add button or remove button nothing happens to the layout of my form. Still, I know that subforms are added (removed) by checking whether they exist with xfa.form.resolveNode methods.

Here are my codes for buttons adding and removing subforms:

//Adding subform
xfa.form.form1.Page1.Container.Added.instanceManager.addInstance(1);

if( xfa.form.resolveNode("form1.Page1.Container.Added[3]") ){
xfa.host.messageBox("3rd exists");
}

//Removing subform
this.parent.instanceManager.removeInstance(this.parent.index);

if( !xfa.form.resolveNode("form1.Page1.Container.Added[3]") )
{
xfa.host.messageBox("3rd does not exist");
}

the form can be found here: http://www.megaupload.com/?d=75D3IQSD

Any ideas of what can be wrong?

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System Configuration
Operating system: Windows XP
Application: LiveCycle Designer Version 7.0