50 NL 6-max: Backdoor flush on paired board

[brettkc]

I'm not certain about what is the correct play on this river, should I be pushing here? no read on villian he's new to table.

Full Tilt Poker
$0.25/$0.50 No Limit Hold'em Ring Game
6 Players
LegoPoker Hand Converter

<font color="black">Stack Sizes</font>
CO: $66.65
BTN: $219
SB: $51.3
Hero (BB): $49.5
UTG: $214.65
MP: $54.90

<font color="black">Preflop:</font> 7[img]/images/graemlins/heart.gif[/img] 9[img]/images/graemlins/heart.gif[/img] ($0.75, 6 players)
UTG folds, MP folds, CO folds, BTN folds, <font color="red">SB raises to $2</font>, Hero calls $1.50

<font color="black">Flop:</font> 4[img]/images/graemlins/heart.gif[/img] 9 8[img]/images/graemlins/spade.gif[/img] ($4, 2 players)
<font color="red">SB bets $2.50</font>, Hero calls $2.50

<font color="black">Turn:</font> 4[img]/images/graemlins/heart.gif[/img] 9 8[img]/images/graemlins/spade.gif[/img] [8[img]/images/graemlins/heart.gif[/img]] ($9, 2 players)
SB checks, <font color="red">Hero bets $6.50</font>, SB calls $6.50

<font color="black">River:</font> 4[img]/images/graemlins/heart.gif[/img] 9 8[img]/images/graemlins/spade.gif[/img] 8[img]/images/graemlins/heart.gif[/img] [5[img]/images/graemlins/heart.gif[/img]] ($22, 2 players)
<font color="red">SB bets $12</font>

[EMc]

Im just calling here. Without a read I cant see a raise being called by much that you beat here. Why would villain shut down on the turn and then come alive on the river?

[jgunnip]

[ QUOTE ]
Why would villain shut down on the turn and then come alive on the river?

[/ QUOTE ]

76 hit their straight?

I'd just call as well as I can't see any value in pushing. Folding is not an option.