Party 3/6: Being checkraised by a LAG when an ace turns...

[chesspain]

Party Poker 3/6 Hold'em (9 handed)

At the time, my opponent had only been at the table for approx. 20 hands, but he already was displaying LAG tendencies. My turn decision was likely influenced by my realization that I've been calling down too many turn raises/checkraises heads-up with less than TP.

Preflop: chesspain is CO with 8[img]/images/graemlins/heart.gif[/img], 8[img]/images/graemlins/club.gif[/img].
<font color="666666">4 folds</font>, <font color="CC3333">MP3 raises</font>, <font color="CC3333">chesspain 3-bets</font>, <font color="666666">3 folds</font>, MP3 calls.

Flop: (7.33 SB) Q[img]/images/graemlins/heart.gif[/img], 6[img]/images/graemlins/diamond.gif[/img], 4[img]/images/graemlins/spade.gif[/img] <font color="blue">(2 players)</font>
MP3 checks, <font color="CC3333">chesspain bets</font>, MP3 calls.

Turn: (4.66 BB) A[img]/images/graemlins/heart.gif[/img] <font color="blue">(2 players)</font>
MP3 checks, <font color="CC3333">chesspain bets</font>, <font color="CC3333">MP3 raises</font>, chesspain folds.

Is this a good bet-fold? If not, what should my plan have been once this ace fell?