[CentOS] My linux keeps logging me off when I run Firefox (how to debug)?

Tue Apr 16 14:33:55 UTC 2013
Rock <RockSockDoc at gmail.com>

On Tue, 16 Apr 2013 09:55:27 +0100, James Pearson wrote:

> Any Xorg crash details will be in /var/log/Xorg.?.log - however, if Xorg 
> has restarted since the crash, then the error should be in 
> /var/log/Xorg.?.log.old
> 
> The error may also be in one of the log files in /var/log/gdm/

Thanks James, 
This is helpful, especially for debugging.

I'm looking through the Xorg.?.log files in /var/log/
Xorg.{0,2,3,4,5,9}.log
Xorg.{0,,2,3,4,5}.log.old

There is a lot there - but I'm not sure what I'm looking for.

Likewise, I'm looking through the files in /var/log/gdm for clues:
:0-greeter.log
:0-greeter.log.{1,2,3,4}
:0.log
:0.log.{1,2,3,4}
:0-slave.log
:0-slave.log.{1,2,3,4}
etc.