I will thanks Akemi for the help, I solved the problem reinstalling the Nvidia drivers. I have also found the cause of the problem, infact seems
that the systems as done an "automatic update" as shown by the yum.log Jun 26 11:50:13 Installed: kernel-devel-2.6.18-308.8.2.el5.x86_64 Jun 26 11:50:14 Updated: kernel-headers-2.6.18-308.8.2.el5.x86_64 Jun 26 11:50:23 Installed: kernel-2.6.18-308.8.2.el5.x86_64 Jun 26 15:13:04 Installed: mesa-libOSMesa-6.5.1-7.8.el5.x86_64 Jun 26 15:13:04 Installed: mesa-libOSMesa-devel-6.5.1-7.8.el5.x86_64 but how was possible it? since I have: 1) disabled the automatic update (or so I believe) 2) I don't have installed yum-autoupdate 3) yum.cron correspond to checkonly.yum.cron 4) in yum.cron.excludexs I have the following row kernel* openafs* *-kdml-* kmod-* *firmware* Regards Max
