X error: can't open display ?

[Dinh-Tuan.Pham@imag.fr]

       Hi,
       After upgrading my sparc box, I notice a very annoying
problem: I can't no longer launch a remote X client from the console
of my sparc. When I log into another machine and lounch an X
application, I get this error message

Xt: can't open display.

THe DISPLAY variable *has been set corectly* and the client machine
*has been allowed to acess the display* through the command xhost. I
suspect the problem might come from the new Xlib or its interaction
with ssh (but ssh has worked nicely before). But I have no clues. Can
any one help me? Should I file a bug report ? It is important that
this problem be solved quickly since theis machine is a production
machine

Here is some info on the package related to X and ssh:

ii  xlibs          4.0.1-12       X Window System client libraries
ii  xlibs-dev      4.0.2-1        X Window System client library development f
ii  xserver-common 4.0.2-1        files and utilities common to all X servers
ii  xserver-xsun   3.3.6-11potato X server for 8-bit Sun framebuffers
ii  ssh-nonfree    1.2.27-6       a secure replacement for rlogin, rsh, and rc

I also have noticed that the file Xsession has been completely
changed. I have retained the old file, but after changing to the new
file, the problem remains. Another thing is that the xserver-xsun is
still of version 3.3.6 while Xlib is of version 4.0.1. But it is scary
to change the server (if apt-get upgrade don't require this), it would
be catastrophic if the new server won't work.

Thank for any help

-- 
PHAM Dinh Tuan                         | e-mail: Dinh-Tuan.Pham@imag.fr
Laboratoire de Modelisation et Calcul  | Tel: +33 4 76 51 44 23
BP 53, 38041 Grenoble cedex 9 (France) | Fax: +33 4 76 63 12 63
-----------------------------------------------------------------------