FTP $750k Gtd: Set v poss flush on turn

[MAF]

Full Tilt Poker
No Limit Holdem Ring game
Blinds: $25/$50
9 players
Converter

Stack sizes:
UTG: $4575
UTG+1: $1890
Hero: $2845
MP2: $2525
MP3: $3420
CO: $3215
Button: $1845
SB: $3815
BB: $2870

Pre-flop: (9 players) Hero is MP1 with 5[img]/images/graemlins/diamond.gif[/img] 5[img]/images/graemlins/club.gif[/img]
<font color="#cc0000">UTG raises to $175</font>, UTG+1 folds, Hero calls, 4 folds, SB calls, BB calls.

Flop: K[img]/images/graemlins/spade.gif[/img] 5[img]/images/graemlins/heart.gif[/img] 7[img]/images/graemlins/heart.gif[/img] ($700, 4 players)
SB checks, BB checks, <font color="#cc0000">UTG bets $250</font>, <font color="#cc0000">Hero raises to $750</font>, 2 folds, UTG calls.

Turn: T[img]/images/graemlins/heart.gif[/img] ($2200, 2 players)
UTG checks, <font color="#cc0000">Hero ?</font>

UTG had seemed fairly solid so far. I couldn't work out if the turn check was a trap or he was scared by the 3rd heart.

Thoughts?