That is really odd (at least I have not seen it before - so odd to me) because the initial Numlock setting after boot is a BIOS Setup Menu setting. So the keyboard software must have been switching it back for some reason. Anyway, I am glad you got it sorted out and thanks for the tip.
Do you like that keyboard? It looks HUGE! And the successor to that model, the G510s
is even bigger! Oddly enough, neither Newegg or Logitech
state the dimensions in the specs.
I finally found them on Amazon and these keyboards are 20.9" wide. That would be a problem for me as my current keyboard, at 18" wide is already as wide as I would want to go and still have sufficient maneuvering room for the rodent on my slide-out keyboard "tray".