Sortie de console mélangée à l'écran X après la mise à niveau de 12.04

Je viens de passer de la 11.10 à la 12.04 et je vois la sortie de la console sur mon écran X. Ce n'est pas lisible, mais parfois, il y a un problème. Ce n'est pas lisible, mais parfois je peux même voir le curseur clignoter. J'utilise également un système multiposte et je vois des déchets sur l'écran lorsque quelqu'un tape sur le deuxième clavier. Un clic sur l'écran efface la sortie de la console, mais elle réapparaît dès que quelqu'un commence à taper.

xorg.conf

Section "ServerLayout"
    Identifier     "Desktop"
    Screen      0  "DesktopScreen" 0 0
    InputDevice    "DesktopMouse"          "CorePointer"
    InputDevice    "DesktopKeyboard"       "CoreKeyboard"
    Option         "AutoAddDevices"        "false"
    Option         "AllowEmptyInput"       "true"
    Option         "AutoEnableDevices"     "false"
EndSection

Section "ServerLayout"
    Identifier     "Desktop2"
    Screen      1  "Desktop2Screen" 0 0
    InputDevice    "Desktop2Mouse"          "CorePointer"
    InputDevice    "Desktop2Keyboard"       "CoreKeyboard"
    Option         "AutoAddDevices"        "false"
    Option         "AllowEmptyInput"       "true"
    Option         "AutoEnableDevices"     "false"
EndSection

Section "Module"
    Load           "dbe"
    Load           "extmod"
    Load           "type1"
    Load           "freetype"
    Load           "glx"
EndSection

Section "Files"
EndSection

Section "ServerFlags"
    Option "AutoAddDevices"     "false"
    Option "AutoEnableDevices"  "false"
    Option "AllowMouseOpenFail" "on"
    Option "AllowEmptyInput"    "on"
    Option "ZapWarning"         "on"
    Option "HandleSepcialKeys"  "off" # Zapping on
    Option "DRI2"               "on"
    Option "Xinerama"           "0"
EndSection

# Desktop Mouse
Section "InputDevice"
    Identifier     "DesktopMouse"
    Driver         "evdev"
    Option         "Device"          "/dev/input/event3"
    Option         "Protocol"        "auto"
    Option         "GrabDevice"      "on"
    Option         "Emulate3Buttons" "no"
    Option         "Buttons"         "5"
    Option         "ZAxisMapping"    "4 5"
    Option         "SendCoreEvents"  "true"
EndSection

# Desktop2 Mouse
Section "InputDevice"
    Identifier     "Desktop2Mouse"
    Driver         "evdev"
    Option         "Device"          "/dev/input/event5"
    Option         "Protocol"        "auto"
    Option         "GrabDevice"      "on"
    Option         "Emulate3Buttons" "no"
    Option         "Buttons"         "5"
    Option         "ZAxisMapping"    "4 5"
    Option         "SendCoreEvents"  "true"
EndSection

Section "InputDevice"
    Identifier     "DesktopKeyboard"
    Driver         "evdev"
    Option         "Device"    "/dev/input/event4"
    Option         "XkbRules"  "xorg"
    Option         "XkbModel"  "105"
    Option         "XkbLayout" "us"
    Option         "Protocol"  "Standard"
EndSection

Section "InputDevice"
    Identifier     "Desktop2Keyboard"
    Driver         "evdev"
    Option         "Device"    "/dev/input/event14"
    Option         "XkbRules"  "xorg"
    Option         "XkbModel"  "105"
    Option         "XkbLayout" "us"
    Option         "Protocol"  "Standard"
EndSection

Section "Monitor"
    Identifier     "Desktop2Monitor"
    VendorName     "Acer"
    ModelName      "Acer G235H"
    HorizSync       30.0 - 83.0
    VertRefresh     56.0 - 75.0
    Option         "DPMS"
EndSection

Section "Monitor"
    Identifier     "DesktopMonitor"
    VendorName     "Acer"
    ModelName      "Acer H213H"
    HorizSync       30.0 - 83.0
    VertRefresh     56.0 - 75.0
    Option         "DPMS"
EndSection

Section "Device"
    Identifier     "EVGACard"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "GeForce GTX 560 Ti"
    Option         "Coolbits" "1"
    BusID          "PCI:2:0:0"
    Screen          0
EndSection

Section "Device"
    Identifier     "XFXCard"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "GeForce GTX 9800"
    Option         "Coolbits" "1"
    BusID          "PCI:5:0:0"
    Screen          0
EndSection

Section "Screen"
    Identifier     "DesktopScreen"
    Device         "EVGACard"
    Monitor        "DesktopMonitor"
    DefaultDepth    24
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection

Section "Screen"
    Identifier     "Desktop2Screen"
    Device         "XFXCard"
    Monitor        "Desktop2Monitor"
    DefaultDepth    24
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection

lightdm.conf

[SeatDefaults]
greeter-session=unity-greeter
#greeter-session=lightdm-razor-greeter
user-session=ubuntu
xserver-allow-tcp=false
xserver-pass-seat-name=true
greeter-pass-seat-id=true

[Seat:0]
xserver-layout=Desktop
xserver-command=/usr/bin/X :0 -layout Desktop -auth /var/run/lightdm/root/:0 -nolisten tcp vt8 -novtswitch -sharevts -background none

[Seat:1]
xserver-layout=Desktop2
xserver-command=/usr/bin/X :1 -layout Desktop2 -auth /var/run/lightdm/root/:1 -nolisten tcp vt9 -novtswitch -sharevts

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