Flop decision to a miniraise with TP and much backdoors

[DonCologne]

Full Tilt Poker
Pot Limit Omaha Ring game
Blinds: $0.50/$1
6 players
Converter

Stack sizes:
UTG: $59.40
UTG+1: $100
CO: $136
Hero: $106.25
SB: $93.80
BB: $23.40

Pre-flop: (6 players) Hero is Button with Q[img]/images/graemlins/club.gif[/img] 9[img]/images/graemlins/diamond.gif[/img] K[img]/images/graemlins/diamond.gif[/img] J[img]/images/graemlins/club.gif[/img]
UTG calls, UTG+1 folds, CO calls, <font color="#cc0000">Hero raises to $5.5</font>, SB calls, 2 folds, CO calls.

Flop: 9[img]/images/graemlins/club.gif[/img] 4[img]/images/graemlins/diamond.gif[/img] 3[img]/images/graemlins/heart.gif[/img] ($18.5, 3 players)
SB checks, CO checks, <font color="#cc0000">Hero bets $12</font>, <font color="#cc0000">SB raises to $28</font>, CO calls, Hero ?

Who would play check behind at the flop? I think this harmless seeing flop is good to bet out here. With which hands will SB make here this gay miniraise?

I had here only top pair, but 2 backdoor flush draws and a bad backdoor straight draw too. I get here 5.4/1 pot odds and with the 9 two pair outs, which will often enough to win the pot and the backdoors I think it is a call here. Who will call here?