Saw same error when using usb-creator-gtk under Ubuntu 12.04 LTS 64bit
$ usb-creator-gtk `menu_proxy_module_load': /usr/bin/python: undefined symbol: menu_proxy_module_load
(usb-creator-gtk:12501): Gtk-WARNING **: Failed to load type module: (null)
Saw same error when using usb-creator-gtk under Ubuntu 12.04 LTS 64bit
$ usb-creator-gtk module_ load': /usr/bin/python: undefined symbol: menu_proxy_ module_ load
`menu_proxy_
(usb-creator- gtk:12501) : Gtk-WARNING **: Failed to load type module: (null)