GDK_Left can't work

[Falls Huang <bhuang qubit-star com>]

Hello!
        I've a problem adding an accelerator to the left arrow key. I've tried
with GDK_Left, GDK_KP_Left and GDK_leftarrow as keysym, but none of
those works.

This is my code :
/*******************************/
    GtkAccelGroup *accel_group;
    GClosure    *closure;       
    GtkWidget *window = gtk_window_new (GTK_WINDOW_TOPLEVEL);

    accel_group = gtk_accel_group_new ();
    closure = g_cclosure_new(G_CALLBACK(gtk_main_quit), window, NULL);
    gtk_accel_group_connect (accel_group, GDK_Left,
                             0,GTK_ACCEL_VISIBLE,closure);
    gtk_window_add_accel_group (GTK_WINDOW (window), accel_group);
/*******************************/

        If I put something else (like GDK_q) in the gtk_accel_group_connect
function, it works (when I press "q" the callback is called) but I can't make the left arrow to work.
 
btw:  I use GTK 2.6.1 from Debian package.

-- 
Regards 
Falls Huang