Plantage du serveur xorg

hello

Bon 1 fois sur 4 l’interface flubox n’abouti pas. je retombe en mode console (tty 1)
la seul chose que j’ai relever dans un dmesg:

[   33.162444] NVRM: RmInitAdapter failed! (0x54:0x38:1748)
[   33.162451] NVRM: rm_init_adapter(0) failed
[   56.466490] NVRM: RmInitAdapter failed! (0x54:0x38:1748)
[   56.466498] NVRM: rm_init_adapter(0) failed

dans /var/log/syslog:

Jun 14 13:36:35 ssd kernel: [   17.348002] eth0: no IPv6 routers present
Jun 14 13:36:35 ssd ntpdate[1943]: step time server 192.33.96.102 offset -6.408809 sec
Jun 14 13:36:44 ssd kernel: [   33.162444] NVRM: RmInitAdapter failed! (0x54:0x38:1748)
Jun 14 13:36:44 ssd kernel: [   33.162451] NVRM: rm_init_adapter(0) failed
Jun 14 13:36:47 ssd acpid: client 1878[0:0] has disconnected
Jun 14 13:36:51 ssd acpid: client connected from 2062[0:0]
Jun 14 13:36:51 ssd acpid: 1 client rule loaded
Jun 14 13:37:08 ssd kernel: [   56.466490] NVRM: RmInitAdapter failed! (0x54:0x38:1748)
Jun 14 13:37:08 ssd kernel: [   56.466498] NVRM: rm_init_adapter(0) failed
Jun 14 13:37:23 ssd acpid: client 2062[0:0] has disconnected
Jun 14 13:37:45 ssd acpid: client connected from 2158[0:0]
Jun 14 13:37:45 ssd acpid: 1 client rule loaded
Jun 14 13:37:49 ssd acpid: client connected from 2158[0:0]
Jun 14 13:37:49 ssd acpid: 1 client rule loaded

une idée ?
Merci d’avance