$2 NL Sit-n-Go at Full tilt

Here's the hand I think I messed up on. The button SB is a HUGE DONKEY so I tried to get chips out of him pre-flop!!!! He donkbets a whole lot with nothing hands. And he'd been caught betting POT on the flop with a drawing hand twice earlier in the game. Any suggestions?

Full Tilt Poker
No Limit Holdem Tournament
Blinds: t50/t100
4 players

Stack sizes:
UTG: t4745
Button: t2020
SB: t3035
Im_new: t3700

Pre-flop: (4 players) Im_new is BB with A K
2 folds, SB calls t50 (pot was t150), Im_new raises to t400, SB calls t300 (pot was t400).

Flop: K 3 2 (t800, 2 players)
SB bets t800, Im_new raises all-in t3300, SB calls all-in t1835.
Uncalled bets: t665 returned to Im_new.

Turn: 7 (t6070, 0 player + 2 all-in - Main pot: t6070)


River: 7 (t6070, 0 player + 2 all-in - Main pot: t6070)


Results:
Final pot: t6070