10NL top pair + flush draw: call or raise?

[pokahpaul]

villain is running 85.7/14.3/3.75 over 20 hands.

PokerStars No-Limit Hold'em, $0.10 BB (6 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

UTG ($24.25)
MP ($14.75)
CO ($9.30)
Button ($9.55)
SB ($12.90)
BB ($2.80)

Preflop:
UTG calls $0.10, MP calls $0.10, CO calls $0.10, <font color="#CC3333">Button raises to $0.8</font>, <font color="#666666">2 folds</font>, UTG calls $0.70, MP calls $0.70, CO folds.

Flop: ($2.65) A[img]/images/graemlins/diamond.gif[/img], 2[img]/images/graemlins/heart.gif[/img], 4[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">UTG bets $0.9</font>, MP folds, <font color="#CC3333">Button raises to $3.1</font>, UTG folds.

Final Pot: $4.45

should i have just flat called his bet?
if so, do i always flat call against all types of villain?

looking at this hand, i'm convinced that there's more value in calling and raising if he fires a second barrel on turn.

[RedBarracuda]

and what is your hand?, and what is your position?

now.. you prolly had Ahx here and you're the BTN, right? .. ok, since you have a nut flush draw and TP against this donk who is obv. on the aggro side, calling might be an answer cause there's not much that he can have that can beat you in the end..
if you're gonna raise it on flop like you did, then make it a pot sized raise..

[pokahpaul]

oh whoops. seems like my hand got cut out. i had AhKh

[DaycareInferno]

i'm pretty much raising that against any opponent.

[stickdude]

His donk bet was just trying to find out if you were scared of the Ace. You're not getting anything else out of him even if you flat call, because that still tells him what he's trying to find out.