[gdm-list] GDM problem with login screen

[Cosmin Neagu <cosmin neagu omnilogic ro>]

Hello everybody,
This is my first email here, so don't judge me or my problem to harsh.
For about 2 weeks i'm having some problems with my laptop and the login 
screen. How the problem apeared:

I was using Ubuntu 8.10, when someday, when I restarted the laptop the 
login screen was flushing continuously and i wasn't able to login 
because no login screen apeared. Only with CTRL+ALT+F1 i could get into 
the sistem. Since anyway i was planning to upgrade to 9.04, i didn't 
bother to see what was happend.

Then i run 9.04 for a few days when the same problem occured. That was 
very ugly, i belived it was because of some bugs in Ubuntu distributions 
or caused by my hardware since it happend on two diferent version.

I heard of Linux Mint, so i have installed it, and after a while the 
same problem, login screen does not load, keeps flushing and playing the 
welcome sound in backgroud continuously - now am writing from an ugly 
windows XP.
Since it apear that it is doing something in the backgroud like it was 
tring to show the login screen i get into console and i looked at some logs.
tail -f /var/log/syslog

May 15 13:00:45 Dell gdmgreeter[8399]: GdkPixbuf-CRITICAL: 
gdk_pixbuf_get_width: assertion `GDK_IS_PIXBUF (pixbuf)' failed
May 15 13:00:45 Dell gdmgreeter[8399]: GdkPixbuf-CRITICAL: 
gdk_pixbuf_get_height: assertion `GDK_IS_PIXBUF (pixbuf)' failed
May 15 13:00:45 Dell gdmgreeter[8399]: GLib-GObject-CRITICAL: 
g_object_unref: assertion `G_IS_OBJECT (object)' failed
May 15 13:00:45 Dell gdmgreeter[8399]: GdkPixbuf-CRITICAL: 
gdk_pixbuf_get_width: assertion `GDK_IS_PIXBUF (pixbuf)' failed
May 15 13:00:45 Dell gdmgreeter[8399]: GdkPixbuf-CRITICAL: 
gdk_pixbuf_get_height: assertion `GDK_IS_PIXBUF (pixbuf)' failed
May 15 13:00:45 Dell gdmgreeter[8399]: GLib-GObject-CRITICAL: 
g_object_unref: assertion `G_IS_OBJECT (object)' failed
May 15 13:00:45 Dell gdmgreeter[8399]: GLib-GObject-WARNING: invalid 
(NULL) pointer instance
May 15 13:00:45 Dell gdmgreeter[8399]: GLib-GObject-CRITICAL: 
g_signal_connect_data: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
May 15 13:00:45 Dell gdmgreeter[8399]: GdkPixbuf-CRITICAL: 
gdk_pixbuf_get_width: assertion `GDK_IS_PIXBUF (pixbuf)' failed
May 15 13:00:45 Dell gdmgreeter[8399]: GdkPixbuf-CRITICAL: 
gdk_pixbuf_get_height: assertion `GDK_IS_PIXBUF (pixbuf)' failed
May 15 13:00:45 Dell gdmgreeter[8399]: GLib-GObject-CRITICAL: 
g_object_unref: assertion `G_IS_OBJECT (object)' failed
May 15 13:00:45 Dell gdmgreeter[8399]: GdkPixbuf-CRITICAL: 
gdk_pixbuf_get_width: assertion `GDK_IS_PIXBUF (pixbuf)' failed
May 15 13:00:45 Dell gdmgreeter[8399]: GdkPixbuf-CRITICAL: 
gdk_pixbuf_get_height: assertion `GDK_IS_PIXBUF (pixbuf)' failed
May 15 13:00:45 Dell gdmgreeter[8399]: GLib-GObject-CRITICAL: 
g_object_unref: assertion `G_IS_OBJECT (object)' failed
May 15 13:00:45 Dell gdmgreeter[8399]: GLib-GObject-WARNING: invalid 
(NULL) pointer instance

Spend a few hours on google, and the problem seemed to be with my 
graphin nvidia card. Finally i have installed the drivers version 180.51 
and everything was ok.
#glxinfo reported everything right.
But today (with Ubuntu 9.04, nvidia 180.51 and all updates done) the 
same problem reapeared.

OK, the logs say like this while the login screen keeps flashing:
- From syslog:
May 19 09:45:45 Dell gdm[2885]: WARNING: Couldn't authenticate user
May 19 09:45:47 Dell gdm[2885]: WARNING: Couldn't authenticate user
May 19 09:45:50 Dell gdm[2885]: WARNING: Couldn't authenticate user
May 19 09:45:52 Dell gdm[2885]: WARNING: Couldn't authenticate user
May 19 09:45:56 Dell gdm[2885]: WARNING: Couldn't authenticate user
May 19 09:45:59 Dell gdm[2885]: WARNING: Couldn't authenticate user
May 19 09:46:00 Dell gdm[2885]: WARNING: Couldn't authenticate user
May 19 09:46:03 Dell gdm[2885]: WARNING: Couldn't authenticate user
May 19 09:46:05 Dell gdm[2885]: WARNING: Couldn't authenticate user
May 19 09:46:07 Dell gdm[2885]: WARNING: Couldn't authenticate user

- From auth.log:
May 19 09:46:01 Dell gdm[2885]: pam_nologin(gdm:auth): cannot determine 
username
May 19 09:46:02 Dell gdm[2885]: pam_nologin(gdm:auth): cannot determine 
username
May 19 09:46:03 Dell gdm[2885]: pam_nologin(gdm:auth): cannot determine 
username
May 19 09:46:04 Dell gdm[2885]: pam_nologin(gdm:auth): cannot determine 
username
May 19 09:46:05 Dell gdm[2885]: pam_nologin(gdm:auth): cannot determine 
username
May 19 09:46:06 Dell gdm[2885]: pam_nologin(gdm:auth): cannot determine 
username
May 19 09:46:07 Dell gdm[2885]: pam_nologin(gdm:auth): cannot determine 
username

The config files:
/etc/pam.d/gdm
#%PAM-1.0
auth    requisite       pam_nologin.so
auth    required        pam_env.so readenv=1
auth    required        pam_env.so readenv=1 envfile=/etc/default/locale
@include common-auth
auth    optional        pam_gnome_keyring.so
@include common-account
session required        pam_limits.so
@include common-session
session optional        pam_gnome_keyring.so auto_start
@include common-password

/etc/pam.d/gdm-autologin
#%PAM-1.0
auth    requisite       pam_nologin.so
auth    required        pam_env.so readenv=1
auth    required        pam_env.so readenv=1 envfile=/etc/default/locale
auth    required        pam_permit.so
@include common-account
session required        pam_limits.so
@include common-session
@include common-password

One more thing. Now, if i try glxinfo it says: Error: unable to open 
display.

So, can anyoane please help me with this problem? i realy like linux for 
what it can do on the server side, but i cannot work without graphic 
interface.