Thx for your fast response. After installing libgtk2.0-0-dbg I tried to reproduce the error and got the following backtrace:
  
(gdb) bt
#0  0xb7359d6a in g_object_ref ()
   from /usr/lib/libgobject-2.0.so.0
#1  0xb7ae322a in gtk_file_chooser_default_add_filter (
    chooser=0x895e3b0, filter=0x8239880)
    at gtkfilechooserdefault.c:5846
#2  0xb7ad61ae in IA__gtk_file_chooser_add_filter (
    chooser=0x895e3b0, filter=0x8239880)
    at gtkfilechooser.c:1557
#3  0xb7ae7b41 in delegate_add_filter (chooser=0x6c3,
    filter=0x8239880) at gtkfilechooserutils.c:253
#4  0xb7ad61ae in IA__gtk_file_chooser_add_filter (
    chooser=0x8977898, filter=0x8239880)
    at gtkfilechooser.c:1557
#5  0xb7ae7b41 in delegate_add_filter (chooser=0x6c3,
    filter=0x8239880) at gtkfilechooserutils.c:253
#6  0xb7ad61ae in IA__gtk_file_chooser_add_filter (
    chooser=0x8959420, filter=0x8239880)
    at gtkfilechooser.c:1557
#7  0x0806e8f7 in totem_add_files ()
#8  0x0806966f in totem_playlist_add_mrl ()
#9  0xb7364273 in g_cclosure_marshal_VOID__VOID ()
   from /usr/lib/libgobject-2.0.so.0
#10 0xb7357678 in g_closure_invoke ()
   from /usr/lib/libgobject-2.0.so.0
#11 0xb7367325 in g_signal_stop_emission ()
   from /usr/lib/libgobject-2.0.so.0
#12 0xb7368e48 in g_signal_emit_valist ()
   from /usr/lib/libgobject-2.0.so.0
#13 0xb7369199 in g_signal_emit ()
   from /usr/lib/libgobject-2.0.so.0
#14 0xb7a7625f in IA__gtk_button_clicked (button=0x80c1b70)
    at gtkbutton.c:834
#15 0xb7a77a9a in gtk_real_button_released (button=0x80c1b70)
    at gtkbutton.c:1369
#16 0xb7364273 in g_cclosure_marshal_VOID__VOID ()
   from /usr/lib/libgobject-2.0.so.0
#17 0xb7357045 in g_cclosure_new_swap ()
   from /usr/lib/libgobject-2.0.so.0
#18 0xb7357678 in g_closure_invoke ()
   from /usr/lib/libgobject-2.0.so.0
#19 0xb736767c in g_signal_stop_emission ()
   from /usr/lib/libgobject-2.0.so.0
#20 0xb7368e48 in g_signal_emit_valist ()
   from /usr/lib/libgobject-2.0.so.0
#21 0xb7369199 in g_signal_emit ()
   from /usr/lib/libgobject-2.0.so.0
#22 0xb7a761dc in IA__gtk_button_released (button=0x80c1b70)
    at gtkbutton.c:826
#23 0xb7a7714c in gtk_button_button_release (widget=0x6c3,
    event=0x8986070) at gtkbutton.c:1262
#24 0xb7b36f20 in _gtk_marshal_BOOLEAN__BOXED (
    closure=0x80ebeb0, return_value=0xbfb7d070,
    n_param_values=2, param_values=0xbfb7d15c,
    invocation_hint=0xbfb7d05c, marshal_data=0xb7a7712b)
    at gtkmarshalers.c:83
#25 0xb7357045 in g_cclosure_new_swap ()
   from /usr/lib/libgobject-2.0.so.0
#26 0xb7357678 in g_closure_invoke ()
   from /usr/lib/libgobject-2.0.so.0
#27 0xb7367a7e in g_signal_stop_emission ()
   from /usr/lib/libgobject-2.0.so.0
#28 0xb7368ba4 in g_signal_emit_valist ()
   from /usr/lib/libgobject-2.0.so.0
#29 0xb7369199 in g_signal_emit ()
   from /usr/lib/libgobject-2.0.so.0
#30 0xb7c18caf in gtk_widget_event_internal (
    widget=0x80c1b70, event=0x8986070) at gtkwidget.c:3735
#31 0xb7b3569d in IA__gtk_propagate_event (widget=0x80c1b70,
    event=0x8986070) at gtkmain.c:2175
#32 0xb7b35aab in IA__gtk_main_do_event (event=0x8986070)
    at gtkmain.c:1412
#33 0xb79d9c2c in gdk_event_dispatch (source=0x6c3,
    callback=0, user_data=0x0) at gdkevents-x11.c:2291
#34 0xb72694e7 in g_main_context_dispatch ()
   from /usr/lib/libglib-2.0.so.0
#35 0xb726c4d6 in g_main_context_check ()
   from /usr/lib/libglib-2.0.so.0
#36 0xb726c7f8 in g_main_loop_run ()
   from /usr/lib/libglib-2.0.so.0
#37 0xb7b34da5 in IA__gtk_main () at gtkmain.c:991
#38 0x08063a9b in main ()
(gdb)