25NL 99 vs Shortstack Facing Flop Min Raise

[Bodhidharma]

Villain 36/6/2 after a few hundred hands

Not really sure if I'm ahead enough of the time here to call. These min-raises confuse me. I could see this with over cards, TT+ flush draw, or trips. I have no clue.

Ultimate Bet - No Limit Hold'em Cash Game - $0.10/$0.25 Blinds - 6 Players - (LegoPoker HH Converter)

SB: $20.93
BB: $70.17
UTG: $39.22
Hero (MP): $32.06
CO: $9.62
BTN: $25.08

Preflop: Hero is dealt 9[img]/images/graemlins/diamond.gif[/img] 9[img]/images/graemlins/club.gif[/img] (6 Players)
UTG folds, <font color="red">Hero raises to $1.00</font>, CO calls $1.00, 3 folds

Flop: ($2.35) 3[img]/images/graemlins/heart.gif[/img] K[img]/images/graemlins/spade.gif[/img] K[img]/images/graemlins/heart.gif[/img] (2 Players)
<font color="red">Hero bets $1.50</font>, <font color="red">CO raises to $3.00</font>, <font color="red">Hero raises to $14.50??</font>