Comment 12 for bug 478245

Ubuntu 13.10
Keyboard: Corsair Vengeance K60
Unity DE

Pressing the numlock key doesn't toggle numlock, it just remains off. xev(1) shows these events when pressing the key:

KeyPress event, serial 40, synthetic NO, window 0x4200001,
    root 0xde, subw 0x0, time 10592959, (189,1204), root:(255,1257),
    state 0x10, keycode 77 (keysym 0xff7f, Num_Lock), same_screen YES,
    XLookupString gives 0 bytes:
    XmbLookupString gives 0 bytes:
    XFilterEvent returns: False

KeyRelease event, serial 40, synthetic NO, window 0x4200001,
    root 0xde, subw 0x0, time 10593053, (189,1204), root:(255,1257),
    state 0x10, keycode 77 (keysym 0xff7f, Num_Lock), same_screen YES,
    XLookupString gives 0 bytes:
    XFilterEvent returns: False

I managed to work around it using numlockx(1), but it's not a good solution for any non-technical users, and it doesn't allow me to toggle numlock easily.