[gdm-list] authorisation mis-message

[root <soso kol co nz>]

"Server Authorisation Directory (daemon/ServAuthDir) is set to /var/gdm 
but is not owned by user "gdm" and group "gdm". Please correct the 
ownership or gdm configuration in .... gdm.conf and restart gdm"

I type intermittently between repeated X crashes. My /var/gdm IS 
"gdm:gdm 750" as specified (though another lengthy doc says ServAuthDir 
should be "root:gdm 1770" but that doesn't fix the problem either!).
Similar problems googled (& on this mail-list) receive similar advice -- 
and perhaps remain unsolved just because changing ownership and 
permissions doesn't quite do it?

Yes, I inadvertantly altered ownership and permissions in the first 
place, solving another problem, but causing this one.  So, trying to 
recover the required settings -- but they cannot simply be the ones 
given in the mis-message!

Any thoughts about what ELSE needs to be done would be helpful.

Sean Daly