Top pair+nut flush draw vs tight player

[curtains]

Can anyone find a fold here? The guy is very tight, I felt that the best case scenario was that I was up against AK with no heart, but this is really stretching it given the action (limp-call PF). I have a hard time making big laydowns here, but I feel like I'm losing about $20-$30 worth of EV on average by calling here against this particular player. Anyone think it's crazy to even consider folding here?

Also this is the only Hand Converter in the FAQ I could get to work, am I doing something wrong? Even this didn't work, I had to manually enter the BB going allin.

Full Tilt Poker
$/$ No Limit Hold'em Ring Game
9 Players
LegoPoker Hand Converter

<font color="black">Stack Sizes</font>
SB: $583.20 in chips
BB: $271.55 in chips
UTG: $81 in chips
UTG+1: $447.15 in chips
Hero (UTG+2): $493.80 in chips
MP1: $394 in chips
MP2: $231.50 in chips
MP3: $339.60 in chips
CO: $405.70 in chips

<font color="black">Preflop:</font> A[img]/images/graemlins/heart.gif[/img] K[img]/images/graemlins/diamond.gif[/img] ($0, 9 players)
SB: folds, BB: calls $4, UTG: folds, UTG+1: folds, MP1: folds, MP2: calls $20, MP3: folds, CO: folds, BB: calls $16

<font color="black">Flop:</font> 6[img]/images/graemlins/heart.gif[/img] K[img]/images/graemlins/heart.gif[/img] 5[img]/images/graemlins/heart.gif[/img] ($40, 9 players)
BB: checks, <font color="red">Hero: bets $40</font>, BB raises allin