i m running ubuntu 8.10 .unable to login as a user in gui mode.
 

I am running Ubuntu 8.10 and unable to login as a user in gui. Can login as root fine. Trying to login as a user gives me error:
Your session lasted less than 10 seconds. if you have not logged yourself out, this means that there is some installation problem or you might be out of diskspace.
View details(~/.xsession-errors file)
/etc/gdm/Xsession:Beginning session setup...
setting IM through im-switch for locale=en_US.
Start IM through /etc/X11/xinit/xinpur.d/all_ALL linked to /
Could not tell if SELinux is enabled: Permission denied
SELinux pre-installation failed
EOF in dbus-launch reading address from bus daemon

Any help would be appreciated. Thanks

There may be an installation/configuration. I'm not sufficiently knowledgable to be able to tell you where to look for the solution.

The only time I've had such a problem, it was a matter of too little partiton space: in particular, the partition in which /tmp is located.

When you log in to GUI mode, tmp files are created for the desktop. If the partition is too small, you can't create the tmp files, and you are dropped to text mode. The solution is to do some house cleaning: clear out browser caches, tmp files in /tmp, etc. Also, it there is room to do so, resize the partition to make it larger.