Aggressive opponent plays a dangerous board passively

[rikz]

Villain is in my PT database and the HUD reads tight aggressive with a 27% V$PIP / 12% PFR / 2.6 total aggression post flop.

The flop has a pair and a flush draw, but the preflop raiser, who is aggressive, plays passively until the river.

Villain seems like a decent enough player. So, what is going on here by the time it gets to the river? Is this a busted flush draw (which is what I suspected when I check-raised his min-bet on the flop)? AA, KK and AQ would not play this passively? Something else?

Comments on all streets, especially my flop check-raise of his min-bet, and then my call on the turn are much appreciated.

Party Poker No-Limit Hold'em (7 handed) converter

CO ($9)
Button ($27.70)
SB Hero ($25.50)
BB Villain ($51.10)
UTG ($25)
MP1 ($24.40)
MP2 ($27.85)

Preflop: Hero is SB with 8[img]/images/graemlins/club.gif[/img], 8[img]/images/graemlins/spade.gif[/img]. Hero posts a blind of $0.10. UTG posts a blind of $0.25.
UTG (poster) checks, <font color="#666666">2 folds</font>, CO calls $0.25, Button calls $0.25, Hero (poster) completes, <font color="#CC3333">BB Villain raises to $1.5</font>, UTG calls $1.50, CO calls $1.50, Button folds, Hero calls $1.50.

Flop: ($7.25) 6[img]/images/graemlins/diamond.gif[/img], 6[img]/images/graemlins/spade.gif[/img], Q[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(4 players)</font>
Hero checks, <font color="#CC3333">Villain bets $1</font>, UTG folds, CO folds, <font color="#CC3333">Hero raises to $6</font>, Villain calls $5.

Turn: ($19.25) 5[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, <font color="#CC3333">(Opponent Alias) bets $1</font>, Hero calls $1.

River: ($21.25) T[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, <font color="#CC3333">Villain bets $10</font>,

Hero ... What do you do - or would you have even reached this point?

Thanks.