$200NL Turned Set vs Habitual Slow Player

[DaSwam]

Opponent is somewhat tricky, but my notes indicate he loves to slow play. The button raise could mean anything, but the check behind scared me more than the typical c-bet. What's the correct line on the turn?

Full Tilt No-Limit Hold'em, $2 BB (9 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

MP1 ($47.60)
Hero ($276.45)
MP3 ($72)
CO ($218.50)
Button Opponent ($311.40)
SB ($39)
BB ($139.30)
UTG ($207.25)
UTG+1 ($172.75)

Preflop: Hero is MP2 with 4[img]/images/graemlins/club.gif[/img], 4[img]/images/graemlins/diamond.gif[/img].
<font color="#666666">3 folds</font>, Hero calls $2, <font color="#666666">2 folds</font>, <font color="#CC3333">Button Opponent raises to $9</font>, <font color="#666666">2 folds</font>, Hero calls $7.

Flop: ($21) A[img]/images/graemlins/spade.gif[/img], 9[img]/images/graemlins/club.gif[/img], J[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, Opponent checks.

Turn: ($21) 4[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets $15</font>, <font color="#CC3333">Opponent raises to $45</font>, Hero ???