Apres quelques recherches complémentaire sur le site ubuntu, j'ai trouvé ca :
Blank screen with some ATI hardware
* People with ATI display adapters may get a blank screen when loading X due to the driver being unable to initialize certain hardware. Upstream is working on it, and hopefully we'll be able to release an update for 7.10 soon after the release. In the meantime, add 'Option "LVDSBiosNativeMode" "false"' to the driver section of xorg.conf. Bug #132716
Tu dois avoir raison... je vais faire les tests ce soir ;)
[^] # Re: probleme de configuration
Posté par Corto . En réponse au message Problème d'affichage graphique. Évalué à 1.
Blank screen with some ATI hardware
* People with ATI display adapters may get a blank screen when loading X due to the driver being unable to initialize certain hardware. Upstream is working on it, and hopefully we'll be able to release an update for 7.10 soon after the release. In the meantime, add 'Option "LVDSBiosNativeMode" "false"' to the driver section of xorg.conf. Bug #132716
Tu dois avoir raison... je vais faire les tests ce soir ;)
Merci,
Corto