Modal Navigation Titlebar Bug

Create a mashup (mashup A) that has a navigation button on it.  The navigation button navigates to another mashup (mashup B) with a title bar and close button.  Mashup B has a navigation button to mashup C, this button is set to display no title bar or close button.  Mashup C has a button that triggers the close if modal event.

Display A and navigate to B.  Everything works as expected ie mashup B is displayed with titlebar and close button.

Navigate from B to C.  Again all ok.  C is displayed with no title bar.

Press the button on C to active the close if modal event.  C disappears and B is returned to focus.

At this point the title bar and close button of B disappear but the contents of B remain visible.  The titlebar and close button should remain visible after mashup C is closed.