The NumLock and the keypad is so weired in Ubuntu.

I have two computers, A is a desktop, with USB keyboard, B is a laptop, with laptop keyboard and another USB keyboard.

On the desktop A, whether the NumLock is on or off, the number keys on the keypad just don't work. Also the NumLock LED is always off.

The logs shown in xev:

KeyPress event, serial 36, synthetic NO, window 0x6800001,
    root 0xb0, subw 0x0, time 9541332, (172,-12), root:(1846,452),
    state 0x0, keycode 77 (keysym 0xff7f, Num_Lock), same_screen YES,
    XLookupString gives 0 bytes: 
    XmbLookupString gives 0 bytes: 
    XFilterEvent returns: False

KeyRelease event, serial 36, synthetic NO, window 0x6800001,
    root 0xb0, subw 0x0, time 9541412, (172,-12), root:(1846,452),
    state 0x0, keycode 77 (keysym 0xff7f, Num_Lock), same_screen YES,
    XLookupString gives 0 bytes: 
    XFilterEvent returns: False

And on the laptop B, I found that, when the NumLock is on, then many key combinations won't work. For example, generally Ctrl-A is used to select all, but it won't work when NumLock is on.

The logs shown in xev:

(no log when pressed Fn+NumLock on the laptop keyboard)

Logs when pressed the NumLock on the USB keyboard:

(Switch On)

KeyPress event, serial 40, synthetic NO, window 0xb600001,
    root 0xac, subw 0x0, time 22187595, (102,107), root:(1198,133),
    state 0x10, keycode 77 (keysym 0xff7f, Num_Lock), same_screen YES,
    XLookupString gives 0 bytes: 
    XmbLookupString gives 0 bytes: 
    XFilterEvent returns: False

PropertyNotify event, serial 40, synthetic NO, window 0xb600001,
    atom 0x1b8 (XKLAVIER_STATE), time 22187601, state PropertyNewValue

KeyRelease event, serial 40, synthetic NO, window 0xb600001,
    root 0xac, subw 0x0, time 22187723, (102,107), root:(1198,133),
    state 0x10, keycode 77 (keysym 0xff7f, Num_Lock), same_screen YES,
    XLookupString gives 0 bytes: 
    XFilterEvent returns: False

(Switch Off)

KeyPress event, serial 40, synthetic NO, window 0xb600001,
    root 0xac, subw 0x0, time 22187899, (102,107), root:(1198,133),
    state 0x0, keycode 77 (keysym 0xff7f, Num_Lock), same_screen YES,
    XLookupString gives 0 bytes: 
    XmbLookupString gives 0 bytes: 
    XFilterEvent returns: False

PropertyNotify event, serial 40, synthetic NO, window 0xb600001,
    atom 0x1b8 (XKLAVIER_STATE), time 22187904, state PropertyNewValue

KeyRelease event, serial 40, synthetic NO, window 0xb600001,
    root 0xac, subw 0x0, time 22188003, (102,107), root:(1198,133),
    state 0x10, keycode 77 (keysym 0xff7f, Num_Lock), same_screen YES,
    XLookupString gives 0 bytes: 
    XFilterEvent returns: False