That bug has been opened on https://launchpad.net/bugs/88019

"Binary package hint: xchat-gnome

I don't know if that was what triggered the crash, but I was (trying to) change the spell checking settings in xchat when the crash happened.
...
Package: xchat-gnome 1:0.16-0ubuntu2
...
http://librarian.launchpad.net/6532118/88019.apport
...
 #0  0x00002b07c81d9564 in gtk_list_store_set_valist_internal (list_store=0xb2e730, iter=0x7fffe47afbd0, emit_signal=0x7fffe47afacc, maybe_need_sort=0x7fffe47afac8, 
     var_args=0x7fffe47afaf0) at gtkliststore.c:740
 	value = {g_type = 0, data = {{v_int = 0, v_uint = 0, v_long = 0, v_ulong = 0, v_int64 = 0, v_uint64 = 0, v_float = 0, v_double = 0, v_pointer = 0x0}, {v_int = 0, 
       v_uint = 0, v_long = 0, v_ulong = 0, v_int64 = 0, v_uint64 = 0, v_float = 0, v_double = 0, v_pointer = 0x0}}}
 	error = (gchar *) 0x0
 	column = -1408540288
 	func = (GtkTreeIterCompareFunc) 0
 	__PRETTY_FUNCTION__ = "gtk_list_store_set_valist_internal"
 #1  0x00002b07c81dae1d in IA__gtk_list_store_set_valist (list_store=0xb2e730, iter=0x7fffe47afbd0, var_args=0x7fffe47afaf0) at gtkliststore.c:792
 	emit_signal = 1
 	maybe_need_sort = 1
 	__PRETTY_FUNCTION__ = "IA__gtk_list_store_set_valist"
 #2  0x00002b07c81daf08 in IA__gtk_list_store_set (list_store=0x7fffe47afa60, iter=0x7fffe47afa60) at gtkliststore.c:831
 	var_args = {{gp_offset = 40, fp_offset = 48, overflow_arg_area = 0x7fffe47afbd0, reg_save_area = 0x7fffe47afb10}}
 #3  0x0000000000430c07 in gconf_languages_changed (client=<value optimized out>, cnxn_id=<value optimized out>, entry=<value optimized out>, store=0xb2e730)
     at /build/buildd/xchat-gnome-0.16/./src/fe-gnome/preferences-page-spellcheck.c:157
 	iter = {stamp = -630982143, user_data = 0xc42b30, user_data2 = 0x0, user_data3 = 0x0}
 	lang = (gchar *) 0x2aaaac0c0b70 "da"
 	active = <value optimized out>
 	err = (GError *) 0x0
 	new_languages = (GSList *) 0xcd8130
 	old_languages = <value optimized out>
 #4  0x00002b07c7288d32 in gconf_listeners_notify (listeners=0x6d9d20, all_above=0x8137d0 "/apps/xchat/spellcheck/languages", callback=0x2b07c7295a40 <notify_listeners_callback>, 
     user_data=0x7fffe47afca0) at gconf-listeners.c:589
 No locals.
 #5  0x00002b07c7295e50 in notify_one_entry (client=0x6c4e40, entry=0xb18560) at gconf-client.c:2409
 	cae = {client = 0x6c4e40, entry = 0xb18560}
 #6  0x00002b07c7295f12 in notify_idle_callback (data=<value optimized out>) at gconf-client.c:2449
 	entry = (GConfEntry *) 0xb18560
 	client = (GConfClient *) 0x6c4e40
 #7  0x00002b07c993d794 in IA__g_main_context_dispatch (context=0x6c9cb0) at gmain.c:2045
 No locals.
 #8  0x00002b07c99405dd in g_main_context_iterate (context=0x6c9cb0, block=1, dispatch=1, self=<value optimized out>) at gmain.c:2677
 	got_ownership = <value optimized out>
 	max_priority = 200
 	timeout = 0
 	some_ready = 1
 	nfds = <value optimized out>
 	allocated_nfds = <value optimized out>
 	fds = (GPollFD *) 0xab10c0
 	__PRETTY_FUNCTION__ = "g_main_context_iterate"
 #9  0x00002b07c99408ea in IA__g_main_loop_run (loop=0xa22710) at gmain.c:2881
 	got_ownership = <value optimized out>
 	self = (GThread *) 0x689390
 	__PRETTY_FUNCTION__ = "IA__g_main_loop_run"
 #10 0x00002b07c81dcfb3 in IA__gtk_main () at gtkmain.c:1171
 	tmp_list = (GList *) 0x0
 	functions = (GList *) 0x0
 	init = (GtkInitFunction *) 0x7fffe47affa8
 	loop = (GMainLoop *) 0xa22710
 #11 0x0000000000422799 in fe_main () at /build/buildd/xchat-gnome-0.16/./src/fe-gnome/fe-gnome.c:184
 No locals.
 #12 0x000000000045b811 in main (argc=1, argv=0x7fffe47affa8) at /build/buildd/xchat-gnome-0.16/./src/common/xchat.c:782
 	ret = <value optimized out>
StacktraceTop:
 gtk_list_store_set_valist_internal (list_store=0xb2e730, iter=0x7fffe47afbd0, emit_signal=0x7fffe47afacc, maybe_need_sort=0x7fffe47afac8, 
 IA__gtk_list_store_set_valist (list_store=0xb2e730, iter=0x7fffe47afbd0, var_args=0x7fffe47afaf0) at gtkliststore.c:792
 IA__gtk_list_store_set (list_store=0x7fffe47afa60, iter=0x7fffe47afa60) at gtkliststore.c:831
 gconf_languages_changed (client=<value optimized out>, cnxn_id=<value optimized out>, entry=<value optimized out>, store=0xb2e730)
 gconf_listeners_notify (listeners=0x6d9d20, all_above=0x8137d0 "/apps/xchat/spellcheck/languages", callback=0x2b07c7295a40 <notify_listeners_callback>,
ThreadStacktrace:
 .
 Thread 1 (process 12623):
 #0  0x00002b07c81d9564 in gtk_list_store_set_valist_internal (list_store=0xb2e730, iter=0x7fffe47afbd0, emit_signal=0x7fffe47afacc, maybe_need_sort=0x7fffe47afac8, 
     var_args=0x7fffe47afaf0) at gtkliststore.c:740
 	value = {g_type = 0, data = {{v_int = 0, v_uint = 0, v_long = 0, v_ulong = 0, v_int64 = 0, v_uint64 = 0, v_float = 0, v_double = 0, v_pointer = 0x0}, {v_int = 0, 
       v_uint = 0, v_long = 0, v_ulong = 0, v_int64 = 0, v_uint64 = 0, v_float = 0, v_double = 0, v_pointer = 0x0}}}
 	error = (gchar *) 0x0
 	column = -1408540288
 	func = (GtkTreeIterCompareFunc) 0
 	__PRETTY_FUNCTION__ = "gtk_list_store_set_valist_internal"
 #1  0x00002b07c81dae1d in IA__gtk_list_store_set_valist (list_store=0xb2e730, iter=0x7fffe47afbd0, var_args=0x7fffe47afaf0) at gtkliststore.c:792
 	emit_signal = 1
 	maybe_need_sort = 1
 	__PRETTY_FUNCTION__ = "IA__gtk_list_store_set_valist"
 #2  0x00002b07c81daf08 in IA__gtk_list_store_set (list_store=0x7fffe47afa60, iter=0x7fffe47afa60) at gtkliststore.c:831
 	var_args = {{gp_offset = 40, fp_offset = 48, overflow_arg_area = 0x7fffe47afbd0, reg_save_area = 0x7fffe47afb10}}
 #3  0x0000000000430c07 in gconf_languages_changed (client=<value optimized out>, cnxn_id=<value optimized out>, entry=<value optimized out>, store=0xb2e730)
     at /build/buildd/xchat-gnome-0.16/./src/fe-gnome/preferences-page-spellcheck.c:157
 	iter = {stamp = -630982143, user_data = 0xc42b30, user_data2 = 0x0, user_data3 = 0x0}
 	lang = (gchar *) 0x2aaaac0c0b70 "da"
 	active = <value optimized out>
 	err = (GError *) 0x0
 	new_languages = (GSList *) 0xcd8130
 	old_languages = <value optimized out>
 #4  0x00002b07c7288d32 in gconf_listeners_notify (listeners=0x6d9d20, all_above=0x8137d0 "/apps/xchat/spellcheck/languages", callback=0x2b07c7295a40 <notify_listeners_callback>, 
     user_data=0x7fffe47afca0) at gconf-listeners.c:589
 No locals.
 #5  0x00002b07c7295e50 in notify_one_entry (client=0x6c4e40, entry=0xb18560) at gconf-client.c:2409
 	cae = {client = 0x6c4e40, entry = 0xb18560}
 #6  0x00002b07c7295f12 in notify_idle_callback (data=<value optimized out>) at gconf-client.c:2449
 	entry = (GConfEntry *) 0xb18560
 	client = (GConfClient *) 0x6c4e40
 #7  0x00002b07c993d794 in IA__g_main_context_dispatch (context=0x6c9cb0) at gmain.c:2045
 No locals.
 #8  0x00002b07c99405dd in g_main_context_iterate (context=0x6c9cb0, block=1, dispatch=1, self=<value optimized out>) at gmain.c:2677
 	got_ownership = <value optimized out>
 	max_priority = 200
 	timeout = 0
 	some_ready = 1
 	nfds = <value optimized out>
 	allocated_nfds = <value optimized out>
 	fds = (GPollFD *) 0xab10c0
 	__PRETTY_FUNCTION__ = "g_main_context_iterate"
..."