CVS trunk emacsclient: X11 connection rejected

[Glenn Morris]

With Emacs 22, and two GNU/Linux hosts with a common (NFS)
file-system, I can do this:

>From an X-session running on host1:

host1> emacs -Q -f server-start &
host1> ssh host2
host2> ssh host1 emacsclient --no-wait $PWD/README

which visits the README file in the Emacs running on host1. I often
find this convenient, because I often ssh between various machines and
want to have a single Emacs instance. (The "emacsclient" part is
hidden inside an "emacs" wrapper script that Does The Right Thing
according to the situation.)

If I try the same thing with the CVS trunk, then I get the following
error when trying to run emacsclient:

  X11 connection rejected because of wrong authentication.
  *ERROR*: Connection lost to X server `localhost:10.0'

Is this a multi-tty side-effect, and is there any way around this? Or
should I be doing this a different way now?

(A common file-system is not necessary to see this, you can call
emacsclient to edit eg /tmp/foo.)

TIA.