tried to reproduce this bug on my Thinkpad R40 (ATI Radeon 7500), also running a clean install of dapper, and failed to do so. so, perhaps this has to do w/ TwinView or some other xorg.conf setting and/or the NVidia driver. here's xorg.conf of the above Dell machine:
# /etc/X11/xorg.conf (xorg X Window System server configuration file) # # This file was generated by dexconf, the Debian X Configuration tool, using # values from the debconf database. # # Edit this file with caution, and see the /etc/X11/xorg.conf manual page. # (Type "man /etc/X11/xorg.conf" at the shell prompt.) # # This file is automatically updated on xserver-xorg package upgrades *only* # if it has not been modified since the last upgrade of the xserver-xorg # package. # # If you have edited this file but would like it to be automatically updated # again, run the following command: # sudo dpkg-reconfigure -phigh xserver-xorg Section "Files" FontPath "/usr/share/X11/fonts/misc" FontPath "/usr/share/X11/fonts/cyrillic" FontPath "/usr/share/X11/fonts/100dpi/:unscaled" FontPath "/usr/share/X11/fonts/75dpi/:unscaled" FontPath "/usr/share/X11/fonts/Type1" FontPath "/usr/share/X11/fonts/100dpi" FontPath "/usr/share/X11/fonts/75dpi" # path to defoma fonts FontPath "/var/lib/defoma/x-ttcidfont-conf.d/dirs/TrueType" EndSection Section "Module" Load "i2c" Load "bitmap" Load "ddc" Load "dri" Load "extmod" Load "freetype" Load "glx" Load "int10" Load "type1" Load "vbe" EndSection Section "InputDevice" Identifier "Generic Keyboard" Driver "kbd" Option "CoreKeyboard" Option "XkbRules" "xorg" Option "XkbModel" "pc104" Option "XkbLayout" "us" EndSection Section "InputDevice" Identifier "Configured Mouse" Driver "mouse" Option "CorePointer" Option "Device" "/dev/input/mice" Option "Protocol" "ExplorerPS/2" Option "ZAxisMapping" "4 5" Option "Emulate3Buttons" "true" EndSection Section "InputDevice" Driver "wacom" Identifier "stylus" Option "Device" "/dev/wacom" # Change to # /dev/input/event # for USB Option "Type" "stylus" Option "ForceDevice" "ISDV4" # Tablet PC ONLY EndSection Section "InputDevice" Driver "wacom" Identifier "eraser" Option "Device" "/dev/wacom" # Change to # /dev/input/event # for USB Option "Type" "eraser" Option "ForceDevice" "ISDV4" # Tablet PC ONLY EndSection Section "InputDevice" Driver "wacom" Identifier "cursor" Option "Device" "/dev/wacom" # Change to # /dev/input/event # for USB Option "Type" "cursor" Option "ForceDevice" "ISDV4" # Tablet PC ONLY EndSection Section "Monitor" Identifier "DELL 1901FP" Option "DPMS" EndSection Section "Device" Identifier "NVIDIA Corporation NV43 [GeForce 6600]" Driver "nvidia" EndSection Section "Screen" Identifier "Default Screen" Device "NVIDIA Corporation NV43 [GeForce 6600]" Monitor "DELL 1901FP" DefaultDepth 24 Option "NoLogo" Option "NvAGP" "2" Option "TwinView" Option "MetaModes" "1280x1024,1280x1024; 1024x768,1024x768" Option "SecondMonitorHorizSync" "30.0 - 80.0" Option "SecondMonitorVertRefresh" "56.0 - 76.0" Option "TwinViewOrientation" "RightOf" SubSection "Display" Depth 1 Modes "1280x1024" "1152x864" "1024x768" "800x600" "720x400" "640x480" EndSubSection SubSection "Display" Depth 4 Modes "1280x1024" "1152x864" "1024x768" "800x600" "720x400" "640x480" EndSubSection SubSection "Display" Depth 8 Modes "1280x1024" "1152x864" "1024x768" "800x600" "720x400" "640x480" EndSubSection SubSection "Display" Depth 15 Modes "1280x1024" "1152x864" "1024x768" "800x600" "720x400" "640x480" EndSubSection SubSection "Display" Depth 16 Modes "1280x1024" "1152x864" "1024x768" "800x600" "720x400" "640x480" EndSubSection SubSection "Display" Depth 24 Modes "1280x1024" "1152x864" "1024x768" "800x600" "720x400" "640x480" EndSubSection EndSection Section "ServerLayout" Identifier "Default Layout" Screen "Default Screen" InputDevice "Generic Keyboard" InputDevice "Configured Mouse" InputDevice "stylus" "SendCoreEvents" InputDevice "cursor" "SendCoreEvents" InputDevice "eraser" "SendCoreEvents" EndSection Section "DRI" Mode 0666 EndSection -- reproducible X restarts involving GdkPixbuf-CRITICAL https://launchpad.net/bugs/51425 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs