overcards versus maniac and CS

BB is the biggest maniac i've ever seen, 88/46/2.21 (he has capped preflop with 62), UTG is a calling station, 35/7/0.35. i got frustrated here because UTG showed A8, BB showed trash as usual so i would have won the hand. how far should i go on these types of hands? i guess since UTG is a CS he doesn't have a hand unless he shows aggression.

Party Poker 0.50/1 Hold'em (6 max, 4 handed) FTR converter on zerodivide.cx

Preflop: Hero is SB with A[img]/images/graemlins/spade.gif[/img], T[img]/images/graemlins/club.gif[/img].
<font color="#CC3333">UTG raises</font>, <font color="#666666">1 fold</font>, Hero calls, BB calls.

Flop: (6 SB) 2[img]/images/graemlins/heart.gif[/img], 5[img]/images/graemlins/heart.gif[/img], 4[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(3 players)</font>
Hero checks, <font color="#CC3333">BB bets</font>, UTG calls, Hero calls.

Turn: (4.50 BB) 2[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(3 players)</font>
Hero checks, <font color="#CC3333">BB bets</font>, UTG calls, Hero folds.

River: (6.50 BB) 9[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">BB bets</font>, UTG calls.

Final Pot: 8.50 BB