I can confirm this is occurring in feisty too. For whatever reason, gnome-session is not writing back a response to connections. The connections are being accepted, which means the gdk mainloop (as the g_io_add_watch is driven by it) is still running.
I'm going to examine the source code more, as this is a very annoying bug. -- Unable to start applications after suspend/hibernation https://launchpad.net/bugs/49221 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs