On my laptop (Dell XPS1330) multimedia keys work fine by default, but, when I enable "Show position of pointer when the control key is pressed" from gnome-mouse-properties, only volume level keys keep working, while play/pause, skip-to-next or to previous stop to work

This is xev output when it's working ok:
FocusOut event, serial 32, synthetic NO, window 0x3c00001,
    mode NotifyGrab, detail NotifyAncestor

FocusIn event, serial 32, synthetic NO, window 0x3c00001,
    mode NotifyUngrab, detail NotifyAncestor

KeymapNotify event, serial 32, synthetic NO, window 0x0,
    keys:  4294967254 0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   
           0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   



And the following when it breaks:
FocusOut event, serial 32, synthetic NO, window 0x3c00001,
    mode NotifyGrab, detail NotifyAncestor

FocusIn event, serial 32, synthetic NO, window 0x3c00001,
    mode NotifyUngrab, detail NotifyAncestor

KeymapNotify event, serial 32, synthetic NO, window 0x0,
    keys:  125 0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   
           0   0   0   0   0   16  0   0   0   0   0   0   0   0   0   0   

KeyRelease event, serial 32, synthetic NO, window 0x3c00001,
    root 0x13c, subw 0x0, time 18894380, (526,481), root:(530,562),
    state 0x0, keycode 172 (keysym 0x1008ff14, XF86AudioPlay), same_screen YES,
    XLookupString gives 0 bytes: 
    XFilterEvent returns: False

Thanks