Adding findbar like the one from Firefox

[Chinh Nguyen <cnguyen stata com>]

I'm trying to add a findbar to the help viewer in my app like the one 
from Firefox.
I've got a window, with a vbox container.  Packed into the vbox are an 
hbox that contains a toolbar, a two column table, another hbox that 
contains the findbar, and a drawing area that is used as a statusbar.  
Only the table is set to expand and fill if the window is resized.
Initially, the findbar is created but hidden.  When the user selects 
find, I gtk_widget_show() the findbar and gtk_widget_hide() it when 
done.  This didn't work correctly at first in GTK1.2 because the window 
would grow by the height of the findbar when it was shown.  To get 
around the problem, I subtracted the size of the findbar from the vbox 
container before showing the widget.  This worked (and is a total 
kludge).
I've been working on porting my app to GTK2 and the kludge no longer 
works.  I commented out the code that resizes the vbox container and 
left it simply as a gtk_widget_show()/gtk_widget_hide() when 
showing/hiding the findbar.  What happens is that the window shrinks a 
little when the findbar is shown and shrinks a little again (apparently 
the same amount) when it is hidden.
What is causing my window (or most likely my vbox container) to shrink? 
 Is there a better way of packing in a widget that is to be 
shown/hidden that won't cause its parent to resize yet still allow any 
siblings to expand and shrink?  TIA.
-Chinh Nguyen
 cnguyen stata com