Backtrace on startup:

#0  _gtk_text_btree_get_chars_changed_stamp (tree=0x1) at /build/buildd/gtk+2.0-2.19.5/gtk/gtktextbtree.c:541
#1  0x00aeb858 in IA__gtk_text_iter_get_offset (iter=0xbfffece4) at /build/buildd/gtk+2.0-2.19.5/gtk/gtktextiter.c:575
#2  0x0053f8fd in Gtk::TextIter::get_offset() const () from /usr/lib/libgtkmm-2.4.so.1
#3  0x0815c79a in gnote::NoteBufferArchiver::deserialize(Glib::RefPtr<Gtk::TextBuffer> const&, Gtk::TextIter const&, sharp::XmlReader&) ()
#4  0x0815e2e5 in gnote::NoteBufferArchiver::deserialize(Glib::RefPtr<Gtk::TextBuffer> const&, Gtk::TextIter const&, std::string const&) ()
#5  0x080d7cc9 in gnote::NoteDataBufferSynchronizer::synchronize_buffer() ()
#6  0x080d8596 in gnote::NoteDataBufferSynchronizer::set_buffer(Glib::RefPtr<gnote::NoteBuffer> const&) ()
#7  0x080d91df in gnote::Note::get_buffer() ()
#8  0x0812e66a in gnote::NoteAddin::get_buffer() const ()
#9  0x08129b26 in gnote::NoteLinkWatcher::on_note_added(std::tr1::shared_ptr<gnote::Note> const&) ()
#10 0x080d547d in sigc::signal1<void, std::tr1::shared_ptr<gnote::Note> const&, sigc::nil>::operator()(std::tr1::shared_ptr<gnote::Note> const&) const ()
#11 0x080cd6a3 in gnote::NoteManager::create_new_note(std::string const&, std::string const&, std::string const&) ()
#12 0x080ce096 in gnote::NoteManager::create(std::string const&, std::string const&) ()
#13 0x080ce50e in gnote::NoteManager::create_start_notes() ()
#14 0x080ce8d0 in gnote::NoteManager::_common_init(std::string const&, std::string const&) ()
#15 0x080cedc5 in gnote::NoteManager::NoteManager(std::string const&, sigc::slot<void, std::tr1::shared_ptr<gnote::Note> const&, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil> const&) ()
#16 0x080bc5ea in gnote::Gnote::main(int, char**) ()
#17 0x080b7b20 in main ()

Backtrace on note opening (when ~/.gnote is created it seems to advance further a bit - applet appears in the notification panel and notes can be opened):

#0  _gtk_text_btree_get_chars_changed_stamp (tree=0x1) at /build/buildd/gtk+2.0-2.19.5/gtk/gtktextbtree.c:541
#1  0x00aeb858 in IA__gtk_text_iter_get_offset (iter=0xbfffe314) at /build/buildd/gtk+2.0-2.19.5/gtk/gtktextiter.c:575
#2  0x0053f8fd in Gtk::TextIter::get_offset() const () from /usr/lib/libgtkmm-2.4.so.1
#3  0x0815c79a in gnote::NoteBufferArchiver::deserialize(Glib::RefPtr<Gtk::TextBuffer> const&, Gtk::TextIter const&, sharp::XmlReader&) ()
#4  0x0815e2e5 in gnote::NoteBufferArchiver::deserialize(Glib::RefPtr<Gtk::TextBuffer> const&, Gtk::TextIter const&, std::string const&) ()
#5  0x080d7cc9 in gnote::NoteDataBufferSynchronizer::synchronize_buffer() ()
#6  0x080d8596 in gnote::NoteDataBufferSynchronizer::set_buffer(Glib::RefPtr<gnote::NoteBuffer> const&) ()
#7  0x080d91df in gnote::Note::get_buffer() ()
#8  0x080efb4e in gnote::NoteWindow::NoteWindow(gnote::Note&) ()
#9  0x080d78e2 in gnote::Note::get_window() ()
#10 0x08111a9e in gnote::NoteMenuItem::on_activate() ()
#11 0x004ed1ba in Gtk::MenuItem_Class::activate_callback(_GtkMenuItem*) () from /usr/lib/libgtkmm-2.4.so.1
#12 0x00def0ec in IA__g_cclosure_marshal_VOID__VOID (closure=0x820e920, return_value=0x0, n_param_values=1, param_values=0x82993b0, 
    invocation_hint=0xbfffe8c0, marshal_data=0x4ed150) at /build/buildd/glib2.0-2.23.3/gobject/gmarshal.c:77
#13 0x00ddf4d9 in g_type_class_meta_marshal (closure=0x820e920, return_value=0x0, n_param_values=1, param_values=0x82993b0, invocation_hint=0xbfffe8c0, 
    marshal_data=0x1c0) at /build/buildd/glib2.0-2.23.3/gobject/gclosure.c:878
#14 0x00de0e52 in IA__g_closure_invoke (closure=0x820e920, return_value=0x0, n_param_values=1, param_values=0x82993b0, invocation_hint=0xbfffe8c0)
    at /build/buildd/glib2.0-2.23.3/gobject/gclosure.c:767
#15 0x00df65ea in signal_emit_unlocked_R (node=<value optimized out>, detail=<value optimized out>, instance=0x832c010, emission_return=0x0, 
    instance_and_params=0x82993b0) at /build/buildd/glib2.0-2.23.3/gobject/gsignal.c:3173
#16 0x00df8204 in IA__g_signal_emit_valist (instance=0x832c010, signal_id=94, detail=0, var_args=0xbfffea7c "\a\244", <incomplete sequence \323>)
    at /build/buildd/glib2.0-2.23.3/gobject/gsignal.c:2976
#17 0x00df86a6 in IA__g_signal_emit (instance=0x832c010, signal_id=94, detail=0) at /build/buildd/glib2.0-2.23.3/gobject/gsignal.c:3033
#18 0x00b77835 in IA__gtk_widget_activate (widget=0x832c010) at /build/buildd/gtk+2.0-2.19.5/gtk/gtkwidget.c:4980
#19 0x00a3e020 in IA__gtk_menu_shell_activate_item (menu_shell=0x831f418, menu_item=0x832c010, force_deactivate=1)
    at /build/buildd/gtk+2.0-2.19.5/gtk/gtkmenushell.c:1223
#20 0x00a40063 in gtk_menu_shell_button_release (widget=0x831f418, event=0x81f3e48) at /build/buildd/gtk+2.0-2.19.5/gtk/gtkmenushell.c:679
#21 0x00a338bd in gtk_menu_button_release (widget=0x831f418, event=0x81f3e48) at /build/buildd/gtk+2.0-2.19.5/gtk/gtkmenu.c:3005
#22 0x00a2bf28 in _gtk_marshal_BOOLEAN__BOXED (closure=0x81f84d0, return_value=0xbfffed24, n_param_values=2, param_values=0x836d8c8, 
    invocation_hint=0xbfffed10, marshal_data=0xa337d0) at /build/buildd/gtk+2.0-2.19.5/gtk/gtkmarshalers.c:84
#23 0x00ddf4d9 in g_type_class_meta_marshal (closure=0x81f84d0, return_value=0xbfffed24, n_param_values=2, param_values=0x836d8c8, 
    invocation_hint=0xbfffed10, marshal_data=0xb4) at /build/buildd/glib2.0-2.23.3/gobject/gclosure.c:878
#24 0x00de0e52 in IA__g_closure_invoke (closure=0x81f84d0, return_value=0xbfffed24, n_param_values=2, param_values=0x836d8c8, invocation_hint=0xbfffed10)
    at /build/buildd/glib2.0-2.23.3/gobject/gclosure.c:767
#25 0x00df6996 in signal_emit_unlocked_R (node=<value optimized out>, detail=<value optimized out>, instance=0x831f418, emission_return=0xbfffee6c, 
    instance_and_params=0x836d8c8) at /build/buildd/glib2.0-2.23.3/gobject/gsignal.c:3281
#26 0x00df8083 in IA__g_signal_emit_valist (instance=0x831f418, signal_id=34, detail=0, var_args=0xbfffeed0 "\374\356\377\277\003")
    at /build/buildd/glib2.0-2.23.3/gobject/gsignal.c:2986
#27 0x00df86a6 in IA__g_signal_emit (instance=0x831f418, signal_id=34, detail=0) at /build/buildd/glib2.0-2.23.3/gobject/gsignal.c:3033
#28 0x00b6fa6e in gtk_widget_event_internal (widget=<value optimized out>, event=0x81f3e48) at /build/buildd/gtk+2.0-2.19.5/gtk/gtkwidget.c:4949
#29 0x00a232e0 in IA__gtk_propagate_event (widget=0x831f418, event=0x81f3e48) at /build/buildd/gtk+2.0-2.19.5/gtk/gtkmain.c:2447
#30 0x00a2481f in IA__gtk_main_do_event (event=0x81f3e48) at /build/buildd/gtk+2.0-2.19.5/gtk/gtkmain.c:1647
#31 0x00d4b3ea in gdk_event_dispatch (source=0x81f6a50, callback=0, user_data=0x0) at /build/buildd/gtk+2.0-2.19.5/gdk/x11/gdkevents-x11.c:2372
#32 0x00e4ff95 in g_main_dispatch (context=0x81f6a98) at /build/buildd/glib2.0-2.23.3/glib/gmain.c:1960
#33 IA__g_main_context_dispatch (context=0x81f6a98) at /build/buildd/glib2.0-2.23.3/glib/gmain.c:2513
#34 0x00e53c98 in g_main_context_iterate (context=0x81f6a98, block=<value optimized out>, dispatch=1, self=0x81cc628)
    at /build/buildd/glib2.0-2.23.3/glib/gmain.c:2591
#35 0x00e541ef in IA__g_main_loop_run (loop=0x833cc60) at /build/buildd/glib2.0-2.23.3/glib/gmain.c:2799
#36 0x00a24e29 in IA__gtk_main () at /build/buildd/gtk+2.0-2.19.5/gtk/gtkmain.c:1219
#37 0x004e89f7 in Gtk::Main::run_impl() () from /usr/lib/libgtkmm-2.4.so.1
#38 0x004e87f2 in Gtk::Main::run() () from /usr/lib/libgtkmm-2.4.so.1
#39 0x080b8f7c in gnote::Gnote::start_tray_icon() ()
#40 0x080bc7f8 in gnote::Gnote::main(int, char**) ()
#41 0x080b7b20 in main ()

Looks like it is failing in the same routine.