RHEL 5 - impossible d'ouvrir une session via xdmcp

Serveur en RHEL 5 à jour.

Le package gdm:
gdm-2.16.0-31.0.1.el5

/etc/gdm/custom.conf:
[xdmcp]
Enable=true

J'utilise xming ( http://sourceforge.net/projects/xming ) et arrive sur l'écran de login.

Ensuite avec n'importe quel utilisateur j'obtiens seulement un écran noir + curseur :(

/var/log/messages:

Mar 11 10:14:49 clans gdm[5977]: Handling message: 'QUERYLOGIN 22317 taki'
Mar 11 10:14:49 clans gdm[5977]: Got QUERYLOGIN taki Mar 11 10:14:49 clans gdm[22317]: gdm_slave_wait_for_login: end verify for 'taki'
Mar 11 10:14:49 clans gdm[22317]: gdm_slave_wait_for_login: got_login for 'taki'
Mar 11 10:14:49 clans gdm[22317]: Sending LOGGED_IN == 1 for slave 22317 Mar 11 10:14:49 clans gdm[5977]: Handling message: 'LOGGED_IN 22317 1'
Mar 11 10:14:49 clans gdm[5977]: Got logged in == TRUE Mar 11 10:14:49 clans gdm[22317]: Sending LOGIN == for slave 22317 Mar 11 10:14:49 clans gdm[5977]: Handling message: 'LOGIN 22317 taki'
Mar 11 10:14:49 clans gdm[5977]: Got LOGIN == taki Mar 11 10:14:49 clans gdm[22317]: gdm_slave_session_start: Attempting session for user 'taki'
Mar 11 10:14:49 clans gdm[22317]: Initial setting: session: 'default' language: ''
Mar 11 10:14:49 clans gdm[22317]: gdm_slave_session_start: Authentication completed. Whacking greeter Mar 11 10:14:49 clans gdm[22317]: slave_waitpid: waiting on 22327 Mar 11 10:14:49 clans gdm[22317]: slave_waitpid: done_waiting Mar 11 10:14:49 clans gdm[22317]: Sending GREETPID == 0 for slave 22317 Mar 11 10:14:49 clans gdm[5977]: Handling message: 'GREETPID 22317 0'
Mar 11 10:14:49 clans gdm[5977]: Got GREETPID == 0

Je suis à court d'idées :(