25 Max - FD + gutshot vs a nit turned aggressive

[UFGatorGuy]

Villain is 16/5/2.5 after 140ish hands. Called preflop because UTG is 48/17 and looks like a spewball. I usually would raise this flop heads up but was giving him credit for a big hand that probably isn't folding, based on his lead into a multiway pot and into the preflop raiser. Do you guys raise this? Call down as far as I did? Comments all over please.

Full Tilt No-Limit Hold'em, $0.25 BB (6 handed) Full Tilt Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

SB ($30.15)
BB ($25)
UTG ($31.20)
MP ($32.05)
CO ($33.60)
Hero ($24.65)

Preflop: Hero is Button with 9[img]/images/graemlins/club.gif[/img], 7[img]/images/graemlins/club.gif[/img].
<font color="#CC3333">UTG raises to $0.85</font>, <font color="#666666">2 folds</font>, Hero calls $0.85, SB calls $0.75, <font color="#666666">1 fold</font>.

Flop: ($2.80) 5[img]/images/graemlins/heart.gif[/img], 2[img]/images/graemlins/club.gif[/img], 6[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">SB bets $2</font>, UTG folds, Hero calls $2.

Turn: ($6.80) 5[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">SB bets $4.25</font>, Hero calls $4.25.

River: ($15.30) T[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">SB bets $10</font>, Hero folds.

Final Pot: $15.30