Gtk Fullscreen on startup at Ubuntu 10.10

I'am programming one kiosk app using GTK+Ubuntu 10.10. All works ok when I run the ap开发者_如何转开发p manually but If I setup it up as a Startup Application on Gnome, it does not become fullscreen. I'am using gtk_window_fullscreen() function to tell it to resize as a fullscreen window. When Gnome starts, it launch the app with its default size without resizing.

Calling gtk_window_fullscreen() a second time, some seconds after being launched, doesn't work.

If I move the mouse pointer over the window once opened, it resizes automatically to a fullscreen status.

Any idea how to get a fullscreen on startup?

Regards

Fullscreen is handled by the window manager, so you may need to make sure your program is launched after the window manager has started.