I have been running Redhat-7.1 for six months, but only recently switched to the newer xfree86 (from 3.3 to 4.0.3). After this upgrade i could only run startx as user root - attempting to startx from non-root produced: PAM authentication failed, cannot start X server. Perhaps you ... console ownership? After reading many man pages & scouring the internet & trying everything that sounded plausible, I eventually resorted to the less plausible, and found the solution: touch /var/lock/console/USERNAME (you do this as root and with your non-root username as USERNAME) Note: I do not run devfs - the person who mentioned this as a possible solution said it was only applicable if you did use devfs. I find it hard to believe that a file whose existence is crucial in the granting of console authorization would be under /var/lock -- surely it should be under /etc ?? After two days of frustration, I feel like complaining about this. But I do not know whom to complain to. Is the problem with PAM or with Redhat mods to pam or with version 4.0.3 of xfree86 ?? P.S. when i used Xwrapper the error message was slightly different: Authentication failed, cannot start X server ...