50NL TPTK meets some resistance

[bravos1]

Villian : 34.6/15.4/1.27 over 100 hands or so at the time.

Full Tilt Poker, $0.25/$0.50 NL Hold'em Cash Game, 5 Players
LeggoPoker Hand History Converter

SB: $96.50
BB: $50.75
Hero (UTG): $119.30
CO: $50.75
BTN: $41.65

Pre-Flop: A[img]/images/graemlins/spade.gif[/img] K[img]/images/graemlins/spade.gif[/img] dealt to Hero (UTG)
<font color="red">Hero raises to $1.75</font>, 2 folds, SB calls $1.50, BB folds

Flop: ($4) 2[img]/images/graemlins/club.gif[/img] 5[img]/images/graemlins/heart.gif[/img] A[img]/images/graemlins/heart.gif[/img] (2 Players)
SB checks, <font color="red">Hero bets $4</font>, SB calls $4

Turn: ($12) 8[img]/images/graemlins/diamond.gif[/img] (2 Players)
SB checks, <font color="red">Hero bets $6</font>, <font color="red">SB raises to $16</font>, Hero calls $10

River: ($44) 6[img]/images/graemlins/club.gif[/img] (2 Players)
<font color="red">SB bets $25</font>, <font color="blue">Hero ???</font>

Should hero be folding to the turn raise?