try looking at your windows power settings also, may give a clue to what maybe a issue, some games don't like to pause and while your out of the game doing something else, eg alt tab in and out, as pause then for some games doesn't always initialize the GUI of the given game or background task etc.
so try power settings, screen saver etc and re test, but turn monitor off, but leave game running, not minimized and see if it still happens, or that's what i would try anyway, as then see if it's a gaming error or a o/s one.
as if it doesn't give an error, but does when it's minimized and paused and you have alt tabbed out, the it's windows, and not the game etc.
if it does give an error when paused, but screen is not minimized and alt tab hasn't been used, it's either the game or background task etc.
imo of course