Observando o meu xorg ele se encontra desta maneira:
Section "Device"
Identifier "Default Device"
Option "NoLogo" "True"
EndSection
o meu sistema é
ricardo@ricardo-M61PMV:~$ lspci
00:00.0 RAM memory: nVidia Corporation MCP61 Memory Controller (rev a1)
00:01.0 ISA bridge: nVidia Corporation MCP61 LPC Bridge (rev a2)
00:01.1 SMBus: nVidia Corporation MCP61 SMBus (rev a2)
00:01.2 RAM memory: nVidia Corporation MCP61 Memory Controller (rev a2)
00:02.0 USB Controller: nVidia Corporation MCP61 USB Controller (rev a3)
00:02.1 USB Controller: nVidia Corporation MCP61 USB Controller (rev a3)
00:04.0 PCI bridge: nVidia Corporation MCP61 PCI bridge (rev a1)
00:05.0 Audio device: nVidia Corporation MCP61 High Definition Audio (rev a2)
00:06.0 IDE interface: nVidia Corporation MCP61 IDE (rev a2)
00:07.0 Bridge: nVidia Corporation MCP61 Ethernet (rev a2)
00:08.0 IDE interface: nVidia Corporation MCP61 SATA Controller (rev a2)
00:08.1 IDE interface: nVidia Corporation MCP61 SATA Controller (rev a2)
00:09.0 PCI bridge: nVidia Corporation MCP61 PCI Express bridge (rev a2)
00:0b.0 PCI bridge: nVidia Corporation MCP61 PCI Express bridge (rev a2)
00:0c.0 PCI bridge: nVidia Corporation MCP61 PCI Express bridge (rev a2)
00:18.0 Host bridge: Advanced Micro Devices [AMD] Family 10h Processor HyperTransport Configuration
00:18.1 Host bridge: Advanced Micro Devices [AMD] Family 10h Processor Address Map
00:18.2 Host bridge: Advanced Micro Devices [AMD] Family 10h Processor DRAM Controller
00:18.3 Host bridge: Advanced Micro Devices [AMD] Family 10h Processor Miscellaneous Control
00:18.4 Host bridge: Advanced Micro Devices [AMD] Family 10h Processor Link Control
02:00.0 VGA compatible controller: nVidia Corporation GF106 [GeForce 450 GTS] (rev a1)
02:00.1 Audio device: nVidia Corporation GF106 High Definition Audio Controller (rev a1)
está correto ele deste tamanho?
Edit: Resolvi este problema seguindo o tópico
http://ubuntuforum-br.org/index.php/topic,69789.0.html