I confirm the behaviour on up-to-date Fedora 14. The same error is raised also by nm-applet and gnome-volume-control-applet.

Actually i stumbled upon this bug while looking for the same error raised by hovering on Dropbox icon, but the messages are displayed in any foreground shell.

I got this same error with another applet. I turned off compiz (compiz started with fusion-icon), and the applet behaved correctly. (i turned compiz back on after i made my changes)

Seems to be some sort of interaction between the applets and compiz (or compiz fusion?)

Let me know if you want me to do any further testing.

I can easily reproduce this on my system using zenity on Fedora 14 : 2.6.35.10-74.fc14.x86_64

  $ zenity --notification --text 'hello'

Hover the mouse over the notification icon and the assertion messages appear:

(zenity:7057): Gdk-CRITICAL **: IA__gdk_window_get_root_coords: assertion `GDK_IS_WINDOW (window)' failed

(zenity:7057): Gdk-CRITICAL **: IA__gdk_window_get_root_coords: assertion `GDK_IS_WINDOW (window)' failed

(zenity:7057): Gdk-CRITICAL **: IA__gdk_window_get_root_coords: assertion `GDK_IS_WINDOW (window)' failed

Could this be a gtk2 issue?

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This is still a bug in EL6 (gtk2-2.24.23-6.el6.x86_64), as can be seen by running the command in comment #3.

Here is a simple program that exhibits the same bug:

#include <gtk/gtk.h>

int main(int argc, char **argv)
{
  GtkStatusIcon *icon;
  gtk_init(&argc, &argv);
  icon = gtk_status_icon_new();
  gtk_status_icon_set_from_stock(icon, GTK_STOCK_YES);
  gtk_status_icon_set_tooltip_text(icon, "Hello, world");
  gtk_main();
  return 0;
}