Ubuntu Ibex to Jaunty, now can't launch terminal

[david-8uUts6sDVDvs2Lz0fTdYFQ at public.gmane.org]

> Hi.  I just updated my work laptop from Intrepid to Jaunty (i686) using
> Update Manager.  Most things seem to work fine (pulseaudio failed to
> allocate shared memory pool, etc), but my big problem is when I launch
> Gnome terminal, I get a dialog box saying  "There was an error creating
> the child process for this terminal".  This is true for the default
> profile, or SSHing to another box.
>
> I tried to use Synaptic to install konsole, and it said "Error failed to
> fork pty".

Some more testing:
I tried launching konsole, and I don't get a prompt.  Switching to a text
tty, I can see my shell is /bin/bash in /etc/passwd, and I can run "bash"
and "sudo bash" from that text tty.  Interestingly, running emacs in X, I
can M-x shell and get a shell, but if I type "bash -v" in that shell, it
hangs.

But this proves emacs is an operating system, not an editor.