I've been thinking about this lately too. It seems like small pairs are -EV because you rarely flop a set and even if you do the raise is generally comming from a mediocre hand that wont pay you off big even if they hit too. If you miss then you're stuck check calling the continuation bet if you think the flop missed them and then giving a free turn/river card that can beat you. Not sure if just folding or reraising is a better strategy... maybe reraise 99+ AQ+ and just fold everything else.