heading hex number is the window's pointer, the "before XXX" means XXX is executed just after this printf.
--------- The dialogbox which doesn't crash -------------------
0xbfe3f36c parent (nil) 1
0xbfe3f36c, before destroy children
0xbfe3f36c before unhook
0xbfe3f36c before show
0xbfe3f36c after show
0xbfe3f36c before del im
0xbfe3f36c before delete wxwindow
0xbfe3f36c before delete widget
0xbfe3f36c done
--------- The window which crashes -------------------
0x8127eb8 parent (nil) 1
0x8127eb8, before destroy children
0x8160fe8 parent 0x8127eb8 1 ---- toplevel destroys 0x8160fe8
0x8160fe8, before destroy children
0x8160fe8 before unhook
0x8160fe8 before show
0x8160fe8 after show
0x8160fe8 before del im
0x8160fe8 before delete wxwindow
0x8160fe8 before delete widget
0x8160fe8 done
0x8127eb8 before unhook
0x8127eb8 before show
0x8127eb8 after show
0x8127eb8 before del im
0x8127eb8 before delete wxwindow
Segmentation fault
-------- Back trace -------------------
(gdb) backtrace
#0 0xb7e633af in ?? ()
#1 0xb753f9db in g_cclosure_marshal_VOID__OBJECT ()
from /usr/lib/libgobject-2.0.so.0
#2 0xb753312b in g_closure_invoke () from /usr/lib/libgobject-2.0.so.0
#3 0xb7543599 in signal_emit_unlocked_R () from /usr/lib/libgobject-2.0.so.0
#4 0xb7544a59 in g_signal_emit_valist () from /usr/lib/libgobject-2.0.so.0
#5 0xb7544c09 in g_signal_emit () from /usr/lib/libgobject-2.0.so.0
#6 0xb788f60a in gtk_widget_propagate_hierarchy_changed_recurse ()
from /usr/lib/libgtk-x11-2.0.so.0
#7 0xb7892d2c in _gtk_widget_propagate_hierarchy_changed ()
from /usr/lib/libgtk-x11-2.0.so.0
#8 0xb789c109 in gtk_widget_unparent () from /usr/lib/libgtk-x11-2.0.so.0
#9 0xb7c14cb0 in gtk_pizza_remove (container=0x80ca1e0, widget=0x80ca250)
at ../wxWidgets-2.7.0/src/gtk/win_gtk.c:638
#10 0xb753f9db in g_cclosure_marshal_VOID__OBJECT ()
from /usr/lib/libgobject-2.0.so.0
#11 0xb75316e9 in g_type_class_meta_marshal ()
from /usr/lib/libgobject-2.0.so.0
#12 0xb753312b in g_closure_invoke () from /usr/lib/libgobject-2.0.so.0
#13 0xb7543a16 in signal_emit_unlocked_R () from /usr/lib/libgobject-2.0.so.0
#14 0xb7544a59 in g_signal_emit_valist () from /usr/lib/libgobject-2.0.so.0
#15 0xb7544c09 in g_signal_emit () from /usr/lib/libgobject-2.0.so.0
#16 0xb76ec0f7 in gtk_container_remove () from /usr/lib/libgtk-x11-2.0.so.0
#17 0xb78974ad in gtk_widget_dispose () from /usr/lib/libgtk-x11-2.0.so.0
#18 0xb75357d1 in g_object_run_dispose () from /usr/lib/libgobject-2.0.so.0
#19 0xb779f98e in gtk_object_destroy () from /usr/lib/libgtk-x11-2.0.so.0
---Type <return> to continue, or q <return> to quit---
#20 0xb78976b5 in gtk_widget_destroy () from /usr/lib/libgtk-x11-2.0.so.0
#21 0xb7c1b82f in ~wxWindow (this=0x0)
at ../wxWidgets-2.7.0/src/gtk/window.cpp:2689