Version:           4.5 (using KDE 4.5.2) 
OS:                Linux

If you go to System Settings > Shortcuts and Gestures and create a custom shortcut which is triggered by pressing the "touchpad off" button on the ASUS 1005HA eeePC it seems to be recognized when you are setting the shortcut but it will not work when actually attempting to use it. When the touchpad off button is pressed, KDE recognizes it as "Tools".

I have verified that the action is executed just as expected using a different keybinding (something like Meta+Shift+Y).

Reproducible: Always

Steps to Reproduce:
On an ASUS eeePC 1005HA, go to System Settings > Shortcuts and Gestures and attempt to bind any action to the "touchpad off" button. Now, attempt to perform said action by pressing the button.

Actual Results:  
Nothing happens.

Expected Results:  
The button should perform the action that was bound to it.

When I press and release the key in xev, the output is as follows:

KeyPress event, serial 38, synthetic NO, window 0x5200001,
root 0xaa, subw 0x0, time 137992, (593,263), root:(596,286),
state 0x0, keycode 191 (keysym 0x1008ff81, XF86Tools), same_screen YES,
XKeysymToKeycode returns keycode: 179
XLookupString gives 0 bytes: 
XmbLookupString gives 0 bytes: 
XFilterEvent returns: False

KeyRelease event, serial 38, synthetic NO, window 0x5200001,
root 0xaa, subw 0x0, time 137992, (593,263), root:(596,286),
state 0x0, keycode 191 (keysym 0x1008ff81, XF86Tools), same_screen YES,
XKeysymToKeycode returns keycode: 179
XLookupString gives 0 bytes: 
XFilterEvent returns: False

Probably the important bit here is the keycode, which is 191.