X11 is not forwarded despite ....

[Eduardo M. A. M. Mendes]

Hello
    I installed openssh in 2 linux and 1 solaris boxes.   X11 works both
linux but everytime I slogin
on the solaris box from a linux box a warning message saying that X11
will not be fowarded is displayed.
All ssh and sshd_config are exactly the same.  What did I do wrong?

    Thanks a lot.

Regards

Ed