xauth failure when tunneling over ssh

[Elliot Isaacson]

Hi,

I've set up X11Forwarding on several linux servers before, but I've 
just wasted a day trying (unsuccessfully) to figure out why I can't 
get it working on freebsd (7.0-RELEASE GENERIC).

I have not changed the defaults in the sshd_config file.

One the client computer:

$ xhost +

$ ssh -Y 192.ip.of.server
Warning: No xauth data; using fake authentication data for X11 
forwarding.

/usr/local/bin/xauth:  creating new authority 
file /home/xxx/.Xauthority
/usr/local/bin/xauth: (stdin):1:  bad display name "unix:10.0" 
in "remove" command
/usr/local/bin/xauth: (stdin):2:  bad display name "unix:10.0" 
in "add" command

[xxx@ ~] kcalc
X11 connection rejected because of wrong authentication.
kcalc: Fatal IO error: client killed

[xxx@ ~] ls -a .Xauth*
<no results>

Now, when I go to the server and login directly, and do a startx, 
the x server starts fine, but there's still no .Xauthority file in 
the home directory. I find that odd.

This also looks strange to me:

[xxx@ ~] ps -aux | grep X
root    1470  0.0  2.7 65456 13668  v0  S     4:01PM   0:01.24 
X :0 -auth /home/xxx/.serverauth.1451 (Xorg)

[xxx@ ~] ls -a /home/xxx/.serverauth*
<no results>

How could it authenticate with a non-existent file?

Any pointers in the right direction would be greatly appreciated.

Thanks,
Elliot