Root password disappears at every login, was "Cannot login as root"

[Patrick O'Callaghan]

On Sun, 2008-11-16 at 13:13 +0100, M. Fioretti wrote:
> On Sun, November 16, 2008 7:00 am, M. Fioretti wrote:
> >
> >>>> I get the login prompt, type root, after a few seconds I get the login
> >>>> prompt again, the pc never asks for a password.
> >
> >
> > after studying the dmesg output... I had an inspiration and disabled
> SELINUX by
> > adding "enforcing 0" at the end of the kernel line in grub.conf.
> 
> that made the password prompt appear and I was able to login as root
> several times.
> 
> After that, I installed with yum at the command line X (with nvidia
> drivers from rpmfusion) and then did a
> 
> yum groupinstall 'Gnome Desktop Environment'
> yum groupinstall XFCE
> 
> without noticing any errors. Then I set inittab to runlevel 5, rebooted
> and got the graphical login screen. Logged in as root, found everything OK
> in Gnome, created a normal user and rebooted.
> 
> Since then, root password doesn't work anymore. If I login as the other
> user it works, but if I login as root or type "su -" I get a "password
> incorrect" message. If I boot in single mode and set again the root
> password I get "all authentication tokens updated successfully" but the
> password doesn't last.
> 
> Next login as root, I get "password incorrect' again
> Any idea on what the problem could be now and why is only the root account
> having it?

Is this F10? If so, be aware that gdm on F10 doesn't allow root to log
in directly.

poc