X forwarding and X11UseLocalhost

[I've posted this to the comp.security.ssh newsgroup but didn't get a
reply, and am hoping to have better luck here.  TIA.]

I've been using X11 forwarding, but since switching from XFree86 to
X.org (on both local and remote hosts, both running Gentoo Linux,
2.6.9 kernel and OpenSSH v3.8.1p1) I've observed that `ssh -X
userid@remotehost' results in DISPLAY being set in the remote shell to
`thishost:0.0' (where thishost is the system system from which I'm
connecting) rather than `localhost:10.0' as it had before.  The server
does have X11UseLocalhost set to `yes' in sshd_config, so I'm a little
stumped.  I'd like to get the old behavior working, rather than use
`xhost +remotehost' on thishost.

Where can I start looking for the cause of this change (short of the
source code itself - I'm hoping it won't come to that and someone will
know the fix off-hand)?

Thanks!

-- 
Michael J. Barillier               | ``When you have to shoot, shoot.
<blackwolf(at)shadizar.dyndns.org> | Don't talk.''
Public key available on request.   |                     -- Tuco Ramirez