Customization of non-dockable toolbars?

Hi,

When you're in Customize mode at runtime, you are allowed to drag buttons away from the non-dockable toolbars, but you are not allowed to add anything to them, and your changes does not appear to be saved. Is this by design or is it perhaps a bug? I have a couple of users who gets confused about this, and I must agree that it doesn't seem very logical :)