gnome-mag doesn't update the screen properly when running through gnopernicus

[Carlos Eduardo Rodrigues Diogenes <cerdiogenes yahoo com br>]

Hi,

I noticed that gnome-mag doesn't update the screen properly when 
runnning through gnopernicus.

To reproduce this behavior, do the following:

   * start the gnopernicus application and iniatilize the magnifier 
service;
   * set the zoom factor to 4x or more;
   * access the GNOME Application menu through Alt+F1;
   * access the first item of the Accessibility submenu through the 
keyboard;
   * access the firs item of the Accessories submenu through the 
keyboard too;

The screen magnifier screen is not updated properly (sometimes the 
screen  is update properly, but often trash is showed or a black 
magnified screen).

Carlos.