dispaly of the Toplevel window

[Eric <eric_zhang newsoft com cn>]

Hello,friends,
    I am new to gtk progromming. I have a problem which about the
displaying of the topleve window.
    when the toplevel window displaying ,the widgets on the toplevel
window would be
flicker and the toplevle window not displaying immediately(gtk
+-2.0,ubuntu 8.04), but if a window which is popup displaying,it would
be display immediately ,the widget on the popup window display on the
same time,who can tell me the reason,thank you very much first.

Eric