Here is the data from my Dell XPS M1210:

KeyPress event, serial 31, synthetic NO, window 0x5000001,
     root 0x1a6, subw 0x0, time 21635300, (-16,592), root:(1068,741),
     state 0x0, keycode 121 (keysym 0x1008ff12, XF86AudioMute), same_screen  
YES,
     XLookupString gives 0 bytes:
     XmbLookupString gives 0 bytes:
     XFilterEvent returns: False

KeyRelease event, serial 34, synthetic NO, window 0x5000001,
     root 0x1a6, subw 0x0, time 21635434, (-16,592), root:(1068,741),
     state 0x0, keycode 121 (keysym 0x1008ff12, XF86AudioMute), same_screen  
YES,
     XLookupString gives 0 bytes:
     XFilterEvent returns: False

KeyPress event, serial 34, synthetic NO, window 0x5000001,
     root 0x1a6, subw 0x0, time 21638650, (-16,592), root:(1068,741),
     state 0x0, keycode 122 (keysym 0x1008ff11, XF86AudioLowerVolume),  
same_screen YES,
     XLookupString gives 0 bytes:
     XmbLookupString gives 0 bytes:
     XFilterEvent returns: False

KeyRelease event, serial 34, synthetic NO, window 0x5000001,
     root 0x1a6, subw 0x0, time 21638856, (-16,592), root:(1068,741),
     state 0x0, keycode 122 (keysym 0x1008ff11, XF86AudioLowerVolume),  
same_screen YES,
     XLookupString gives 0 bytes:
     XFilterEvent returns: False

KeyPress event, serial 34, synthetic NO, window 0x5000001,
     root 0x1a6, subw 0x0, time 21640240, (-16,592), root:(1068,741),
     state 0x0, keycode 123 (keysym 0x1008ff13, XF86AudioRaiseVolume),  
same_screen YES,
     XLookupString gives 0 bytes:
     XmbLookupString gives 0 bytes:
     XFilterEvent returns: False

KeyRelease event, serial 34, synthetic NO, window 0x5000001,
     root 0x1a6, subw 0x0, time 21640412, (-16,592), root:(1068,741),
     state 0x0, keycode 123 (keysym 0x1008ff13, XF86AudioRaiseVolume),  
same_screen YES,
     XLookupString gives 0 bytes:
     XFilterEvent returns: False

KeyPress event, serial 34, synthetic NO, window 0x5000001,
     root 0x1a6, subw 0x0, time 21641618, (-16,592), root:(1068,741),
     state 0x0, keycode 172 (keysym 0x1008ff14, XF86AudioPlay), same_screen  
YES,
     XLookupString gives 0 bytes:
     XmbLookupString gives 0 bytes:
     XFilterEvent returns: False

KeyRelease event, serial 34, synthetic NO, window 0x5000001,
     root 0x1a6, subw 0x0, time 21641858, (-16,592), root:(1068,741),
     state 0x0, keycode 172 (keysym 0x1008ff14, XF86AudioPlay), same_screen  
YES,
     XLookupString gives 0 bytes:
     XFilterEvent returns: False

KeyPress event, serial 34, synthetic NO, window 0x5000001,
     root 0x1a6, subw 0x0, time 21643085, (-16,592), root:(1068,741),
     state 0x0, keycode 173 (keysym 0x1008ff16, XF86AudioPrev), same_screen  
YES,
     XKeysymToKeycode returns keycode: 144
     XLookupString gives 0 bytes:
     XmbLookupString gives 0 bytes:
     XFilterEvent returns: False

KeyRelease event, serial 34, synthetic NO, window 0x5000001,
     root 0x1a6, subw 0x0, time 21643265, (-16,592), root:(1068,741),
     state 0x0, keycode 173 (keysym 0x1008ff16, XF86AudioPrev), same_screen  
YES,
     XKeysymToKeycode returns keycode: 144
     XLookupString gives 0 bytes:
     XFilterEvent returns: False

KeyPress event, serial 34, synthetic NO, window 0x5000001,
     root 0x1a6, subw 0x0, time 21644192, (-16,592), root:(1068,741),
     state 0x0, keycode 171 (keysym 0x1008ff17, XF86AudioNext), same_screen  
YES,
     XKeysymToKeycode returns keycode: 153
     XLookupString gives 0 bytes:
     XmbLookupString gives 0 bytes:
     XFilterEvent returns: False

KeyRelease event, serial 34, synthetic NO, window 0x5000001,
     root 0x1a6, subw 0x0, time 21644347, (-16,592), root:(1068,741),
     state 0x0, keycode 171 (keysym 0x1008ff17, XF86AudioNext), same_screen  
YES,
     XKeysymToKeycode returns keycode: 153
     XLookupString gives 0 bytes:
     XFilterEvent returns: False

KeyPress event, serial 34, synthetic NO, window 0x5000001,
     root 0x1a6, subw 0x0, time 21645630, (-16,592), root:(1068,741),
     state 0x0, keycode 174 (keysym 0x1008ff11, XF86AudioLowerVolume),  
same_screen YES,
     XKeysymToKeycode returns keycode: 122
     XLookupString gives 0 bytes:
     XmbLookupString gives 0 bytes:
     XFilterEvent returns: False

KeyRelease event, serial 34, synthetic NO, window 0x5000001,
     root 0x1a6, subw 0x0, time 21645802, (-16,592), root:(1068,741),
     state 0x0, keycode 174 (keysym 0x1008ff11, XF86AudioLowerVolume),  
same_screen YES,
     XKeysymToKeycode returns keycode: 122
     XLookupString gives 0 bytes:
     XFilterEvent returns: False


On Wed, 05 Nov 2008 15:25:10 +0100, Mario Limonciello <email address hidden>  
wrote:

> mickru and dotcohen:
>
> If your buttons aren't working properly, can you please run "xev" in a
> terminal, press them and paste the output here?  It's possible (and
> likely) the buttons are properly mapped, just KDE4 doesn't know what it
> should be doing with them.
>