Another situation I don't know how to handle

UTG is loose aggressive, but I don't have enough of a read on him to know if he's intelligently or stupidly aggressive.

Party Poker 0.50/1 Hold'em (10 handed) converter

Preflop: Hero is UTG+2 with 8[img]/images/graemlins/heart.gif[/img], 8[img]/images/graemlins/diamond.gif[/img].
UTG calls, <font color="#666666">1 fold</font>, <font color="#CC3333">Hero raises</font>, <font color="#666666">6 folds</font>, BB calls, UTG calls.

Flop: (6.50 SB) 4[img]/images/graemlins/club.gif[/img], 3[img]/images/graemlins/spade.gif[/img], 5[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(3 players)</font>
BB checks, UTG checks, <font color="#CC3333">Hero bets</font>, BB calls, <font color="#CC3333">UTG raises</font>, <font color="#CC3333">Hero 3-bets</font>, BB folds, <font color="#CC3333">UTG caps</font>, Hero calls.

Turn: (7.75 BB) 3[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">UTG bets</font>, Hero calls.

River: (9.75 BB) J[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">UTG bets</font>, Hero calls.

Final Pot: 11.75 BB

The preflop limping combined with the flop check raise and cap tells me he's flopped a set. Did calling to the river make sense?