Concentrating on the Mute Key on Thinkpad X60s:

# lsinput
/dev/input/event0
   bustype : BUS_ADB
   vendor  : 0x1
   product : 0x1
   version : 256
   name    : "Macintosh mouse button emulation"
   bits ev : EV_SYN EV_KEY EV_REL

/dev/input/event1
   bustype : BUS_I8042
   vendor  : 0x1
   product : 0x1
   version : 43860
   name    : "AT Translated Set 2 keyboard"
   phys    : "isa0060/serio0/input0"
   bits ev : EV_SYN EV_KEY EV_MSC EV_LED EV_REP

/dev/input/event2
   bustype : BUS_ISA
   vendor  : 0x1f
   product : 0x1
   version : 256
   name    : "PC Speaker"
   phys    : "isa0061/input0"
   bits ev : EV_SYN EV_SND

/dev/input/event3
   bustype : BUS_HOST
   vendor  : 0x0
   product : 0x2
   version : 0
   name    : "Power Button (FF)"
   phys    : "LNXPWRBN/button/input0"
   bits ev : EV_SYN EV_KEY

/dev/input/event4
   bustype : BUS_HOST
   vendor  : 0x0
   product : 0x5
   version : 0
   name    : "Lid Switch"
   phys    : "PNP0C0D/button/input0"
   bits ev : EV_SYN EV_SW

/dev/input/event5
   bustype : BUS_HOST
   vendor  : 0x0
   product : 0x3
   version : 0
   name    : "Sleep Button (CM)"
   phys    : "PNP0C0E/button/input0"
   bits ev : EV_SYN EV_KEY

/dev/input/event6
   bustype : BUS_HOST
   vendor  : 0x0
   product : 0x6
   version : 0
   name    : "Video Bus"
   phys    : "/video/input0"
   bits ev : EV_SYN EV_KEY

/dev/input/event7
   bustype : BUS_HOST
   vendor  : 0x0
   product : 0x6
   version : 0
   name    : "Video Bus"
   phys    : "/video/input0"
   bits ev : EV_SYN EV_KEY

/dev/input/event8
   bustype : BUS_I8042
   vendor  : 0x2
   product : 0xa
   version : 0
   name    : "TPPS/2 IBM TrackPoint"
   phys    : "isa0060/serio1/input0"
   bits ev : EV_SYN EV_KEY EV_REL

/dev/input/event9
   bustype : BUS_HOST
   vendor  : 0x17aa
   product : 0x5054
   version : 16641
   name    : "ThinkPad Extra Buttons"
   phys    : "thinkpad_acpi/input0"
   bits ev : EV_SYN EV_KEY EV_MSC EV_SW

# input-events -g -t 5 9
/dev/input/event9
   bustype : BUS_HOST
   vendor  : 0x17aa
   product : 0x5054
   version : 16641
   name    : "ThinkPad Extra Buttons"
   phys    : "thinkpad_acpi/input0"
   bits ev : EV_SYN EV_KEY EV_MSC EV_SW

grabbed input device
waiting for events
21:45:00.876229: EV_KEY KEY_MIN_INTERESTING pressed
21:45:00.876242: EV_SYN code=0 value=0
21:45:00.876245: EV_KEY KEY_MIN_INTERESTING released
21:45:00.876249: EV_SYN code=0 value=0
timeout, quitting
released input device

# acpi_listen 
ibm/hotkey HKEY 00000080 00001017

xev does not show the key

showkey
kb mode was RAW
[ if you are trying this under X, it might not work
since the X server is also reading /dev/console ]

press any key (program terminates 10s after last keypress)...
keycode 113 press
keycode 113 release
^Ccaught signal 2, cleaning up...

showkey -s
kb mode was RAW
[ if you are trying this under X, it might not work
since the X server is also reading /dev/console ]

press any key (program terminates 10s after last keypress)...
0xe0 0x20 0xe0 0xa0 
^Ccaught signal 2, cleaning up...

$ lshal -m

Start monitoring devicelist:
-------------------------------------------------
21:54:21.164: computer_logicaldev_input_5 condition ButtonPressed = mute
^C

Still no idea why the screen locks .....