Toolbar context menu showing inside toolbarbutton's xul panel

Toolbar context menu showing inside toolbarbutton's xul panel

I have a toolbarbutton that when clicked, shows a panel. When i right
click the panel i'm getting the following:

This is the same context menu that shows when i click on the main toolbar
or even the toolbarbuttons.
The xul is:
<toolbarpalette id="BrowserToolbarPalette">
<toolbarbutton id="testToolbarIcon"
image="chrome://myext/content/images/aicon.png"
type="panel"
class="toolbarbutton-1 chromeclass-toolbar-additional">
<panel id="testPanel"
type="arrow"
level="parent">
<vbox id="testbox" align="top" width="200" height="200">
<label value="Test Label" />
</vbox>
</panel>
</toolbarbutton>
</toolbarpalette>
Any idea on how to stop this behavior from passing to the panel?