25NL, AK missed flop

[wstaffor]

No real reads, button hasn't been at table very long.

Full Tilt Poker - No Limit Hold'em Cash Game - $0.10/$0.25 Blinds - 5 Players - (LegoPoker Hand History Converter)

Hero (SB): $35.25
BB: $25.00
UTG: $25.00
CO: $11.75
BTN: $27.95

Preflop: Hero is dealt K[img]/images/graemlins/spade.gif[/img] A[img]/images/graemlins/club.gif[/img] (5 Players)
2 folds, <font color="red">BTN raises to $0.85</font>, <font color="red">Hero raises to $3.00</font>, BB folds, BTN calls $2.15

Flop: ($6.25) Q[img]/images/graemlins/club.gif[/img] 9[img]/images/graemlins/club.gif[/img] 5[img]/images/graemlins/spade.gif[/img] (2 Players)
<font color="red">Hero bets $4.00</font>, <font color="red">BTN raises to $12.00</font>, Hero.....

Where, if anywhere, did I screw this up?