100NL, small flush on a 4 straight river

[STARSCREAM.]

Pretty new to the table, villian was running about 35/10/3.5 from datamined stats.

Full Tilt Poker, $0.50/$1 NL Hold'em Cash Game, 6 Players
LeggoPoker Hand History Converter

UTG: $27.35
MP: $54.85
CO: $104.60
BTN: $91
SB: $238.35
Hero (BB): $136.55

Pre-Flop: 7[img]/images/graemlins/spade.gif[/img] 5[img]/images/graemlins/spade.gif[/img] dealt to Hero (BB)
UTG folds, MP calls $1, CO folds, BTN calls $1, SB calls $0.50, Hero checks

Flop: ($4) 7[img]/images/graemlins/diamond.gif[/img] J[img]/images/graemlins/spade.gif[/img] 8[img]/images/graemlins/spade.gif[/img] (4 Players)
SB checks, <font color="red">Hero bets $4</font>, MP folds, BTN calls $4, SB folds

Turn: ($12) 9[img]/images/graemlins/spade.gif[/img] (2 Players)
<font color="red">Hero bets $9</font>, <font color="red">BTN raises to $18</font>, Hero calls $9

River: ($48) 5[img]/images/graemlins/heart.gif[/img] (2 Players)
Hero checks, <font color="red">BTN bets $48</font>