I'm seeing the exact same problem on a ThinkPad X61s, upgraded from Gutsy. The relevant section from xorg.conf:
Section "InputDevice" Identifier "Generic Keyboard" Driver "kbd" Option "CoreKeyboard" Option "XkbRules" "xorg" Option "XkbModel" "pc105" Option "XkbLayout" "no" EndSection
I'm seeing the exact same problem on a ThinkPad X61s, upgraded from Gutsy. The relevant section from xorg.conf:
Section "InputDevice"
Identifier "Generic Keyboard"
Driver "kbd"
Option "CoreKeyboard"
Option "XkbRules" "xorg"
Option "XkbModel" "pc105"
Option "XkbLayout" "no"
EndSection