Xlib: Invalid MIT-MAGIC-COOKIE-1 key

[Anton Shterenlikht]

I've two boxes on which I run X servers, one box is 7.1-prelelease,
the other is 8.0-current, both i386. Both boxes run xorg-server-1.4.2,1.
Both boxes have identical $HOME/.Xauthority.

However, when I connect to another computer with ssh -X and try
to run a client, say xclock, one xserver displays the result fine,
while the other gives:

% xclock
Xlib: connection to "localhost:22.0" refused by server
Xlib: Invalid MIT-MAGIC-COOKIE-1 key
Error: Can't open display: localhost:22.0
%

I spent quite a lot of time looking at what are the differences
between my 2 X servers, but can't see any. This should be a simple
problem, just find what the differences are between the working
and the broken configurations, and implement them. But I can't
find any differences.  

What should I look at to resolve the problem?

many thanks
anton

-- 
Anton Shterenlikht
Room 2.6, Queen's Building
Mech Eng Dept
Bristol University
University Walk, Bristol BS8 1TR, UK
Tel: +44 (0)117 928 8233 
Fax: +44 (0)117 929 4423