Two compatible issues in IE6

Hello,

I have two compatible issues testing in IE6 ONLY with following codes, it works fine in IE8 and FF:
1. After click the button, dialog window doesn't popup and UI turns grey. If comment layout.addComponent(createTree()), it's ok.
2. Field NativeSelect is still selectable after dialog window popup.

Does someone have a solution for the issue? or should I open a bug for DevTeam?

Main Window
...
NativeSelect select = new NativeSelect();
layout.addComponent(select);

Botton button = new Button("Select a tree node");
button.addListener(new Button.ClickListener() {
@Override
public void buttonClick(ClickEvent event) {
Application app = event.getButton().getApplication();
app.getMainWindow().addWindow(new Dlalog());
}
});
layout.addComponent(button);
...

Dialog Window
public Dlalog() {

setCaption("Select a tree node");
setModal(true);
setWidth("400px");
setResizable(false);

VerticalLayout layout = (VerticalLayout) getContent();
layout.setMargin(true);
layout.setSpacing(true);
layout.addComponent(createTree()); // return a com.vaadin.ui.Tree;
...
}

Does someone have a solution for the issue? or should I open a bug for DevTeam?

If it works in all other browsers than IE6 then it is a bug. Please open a bug ticket.