double-click in latest version

[Lixin Tang <ltang auto ugcs caltech edu>]

I just updated glib, gtk+ and Gtk-- from 1.1.2, 1.1.1, 0.9.14 to 1.1.5,
1.1.5, 0.10.1, respectively. After a bit modification of my code I wrote
using older versions, I managed to have the code running in these latest
versions. However, double-click event handling now gives me crashes (see
following). Any clue or suggestions? Thanks in advance!

Lixin Tang
==========
Gtk-WARNING **: invalid cast from (NULL) pointer to `GtkData'

Gtk-WARNING **: invalid cast from (NULL) pointer to `GtkObject'

Gtk---WARNING **: castitem == 0 bug; not again!!! Flaming death...

Gtk---WARNING **: gtkmm_sigsegv(Gtk_Object::Gtk_Object(castitem)):
assertion failed inside gtk--. Please make a stack dump with gdb and send
it to terop@modeemi.cs.tut.fi

Gdk-Message: 
** ERROR **: sigsegv caught