.
Thread 1 (process 5586):
#0  0xb7afd24c in IA__gdk_window_set_opacity (window=0x61706573, opacity=0.5)
    at /build/buildd/gtk+2.0-2.12.3/gdk/x11/gdkwindow-x11.c:6447
	__t = <value optimized out>
	display = <value optimized out>
	cardinal = <value optimized out>
	__PRETTY_FUNCTION__ = "IA__gdk_window_set_opacity"
#1  0xb7f5a96c in fadeout_callback (fadeout=0x83951d8) at libgksu.c:321
	current_time = {tv_sec = 1200245676, tv_usec = 629549}
	elapsed = 0
	percent = 0
#2  0xb78ef1e1 in g_idle_dispatch (source=0x8393568, callback=0x806bcd0, 
    user_data=0x83951d8) at /build/buildd/glib2.0-2.15.1/glib/gmain.c:4142
No locals.
#3  0xb78f0d96 in IA__g_main_context_dispatch (context=0x8070c60)
    at /build/buildd/glib2.0-2.15.1/glib/gmain.c:2064
No locals.
#4  0xb78f4153 in g_main_context_iterate (context=0x8070c60, block=1, 
    dispatch=1, self=0x8071c00)
    at /build/buildd/glib2.0-2.15.1/glib/gmain.c:2697
	got_ownership = <value optimized out>
	max_priority = 200
	timeout = 0
	some_ready = 1
	nfds = <value optimized out>
	allocated_nfds = <value optimized out>
	fds = (GPollFD *) 0x838b1c8
	__PRETTY_FUNCTION__ = "g_main_context_iterate"
#5  0xb78f4537 in IA__g_main_loop_run (loop=0x8198598)
    at /build/buildd/glib2.0-2.15.1/glib/gmain.c:2905
	got_ownership = -1215679200
	self = (GThread *) 0x8071c00
	__PRETTY_FUNCTION__ = "IA__g_main_loop_run"
#6  0xb7bf04d9 in IA__gtk_dialog_run (dialog=0x839b838)
    at /build/buildd/gtk+2.0-2.12.3/gtk/gtkdialog.c:1038
	ri = {dialog = 0x0, response_id = -1, loop = 0x8198598, destroyed = 0}
	response_handler = 73
	unmap_handler = 74
	destroy_handler = 76
	delete_handler = 75
	__PRETTY_FUNCTION__ = "IA__gtk_dialog_run"
#7  0xb7f5ae1f in report_failed_grab (what=FAILED_GRAB_MOUSE) at libgksu.c:631
	dialog = (GtkWidget *) 0x839b838
#8  0xb7f5b136 in grab_keyboard_and_mouse (dialog=0x809c940) at libgksu.c:677
	FD = <value optimized out>
	fl = {l_type = 1, l_whence = 0, l_start = 0, l_len = 0, 
  l_pid = -1208635605}
	status = <value optimized out>
	grab_tries = 17
	lock = 26
	fname = <value optimized out>
	pid = <value optimized out>
#9  0xb7f5b655 in su_ask_password (context=0x8071cf0, 
    prompt=0xb723245e <Address 0xb723245e out of bounds>, data=0x0, 
    error=0xbfd14ff4) at libgksu.c:1017
	command = (gchar *) 0x8078520 "Gestionnaire de paquets Synaptic"
	dialog = (GtkWidget *) 0x809c940
	msg = <value optimized out>
	password = <value optimized out>
	tmp = <value optimized out>
	retvalue = <value optimized out>
	lock = 0
	gksu_quark = 97
#10 0xb7f57e75 in gksu_sudo_full (context=0x8071cf0, 
    ask_pass=0xb7f5b350 <su_ask_password>, ask_pass_data=0x0, 
    pass_not_needed=0xb7f5a170 <no_pass>, pass_not_needed_data=0x0, 
    error=0xbfd14ff4) at libgksu.c:2780
	password = <value optimized out>
	prompt_grab = <value optimized out>
	cmd = <value optimized out>
	buffer = "GNOME_SUDO_PA", 'S' <repeats 242 times>
	argcount = 17
	i = <value optimized out>
	j = 14
	gksu_quark = 97
	xauth = (gchar *) 0x8060408 "/tmp/libgksu-MkvuZr/.Xauthority"
	xauth_env = (gchar *) 0x8060463 "/home/yaya/.Xauthority"
	pid = 5601
	status = 256
	infile = (FILE *) 0x809b700
	outfile = (FILE *) 0x8395070
	parent_pipe = {25, 26}
	child_pipe = <value optimized out>
#11 0xb7f59f57 in gksu_run_full (context=0x8071cf0, ask_pass=0, 
    ask_pass_data=0x0, pass_not_needed=0, pass_not_needed_data=0x0, 
    error=0xbfd14ff4) at libgksu.c:2978
	gconf_client = (GConfClient *) 0x8074a58
	sudo_mode = 1
#12 0x0804baf8 in main (argc=13, argv=) at gksu.c:822
	gconf_client = (GConfClient *) 0x8074a58
	count = 1
	context = (GksuContext *) 0x8071cf0
	error = (GError *) 0x0
	newargc = 14
	newargv = (gchar **) 0x80542d8
	run_mode = 2
	c = <value optimized out>
#13 0xb7763450 in __libc_start_main () from /lib/tls/i686/cmov/libc.so.6
#14 0x0804a3e1 in _start ()