I can see how folding the river could be a mistake. I almost think raising would have been better then calling as it would have the added bonus of facing the button with two more bets but I digress. Here is a hand where I was able to isolate the maniac.
PokerStars 0.05/0.10 Hold'em (10 handed)
converter
Preflop: Hero is Button with 4[img]/images/graemlins/heart.gif[/img], 4[img]/images/graemlins/club.gif[/img]. CO posts a blind of $0.07.
<font color="#666666">
1 fold</font>, UTG+1 calls, <font color="#666666">
3 folds</font>, MP3 calls, CO (poster) checks, Hero calls, SB completes, <font color="#CC3333">BB raises</font>, UTG+1 calls, MP3 calls, CO folds, Hero calls, SB calls.
Flop: (11.40 SB) 9[img]/images/graemlins/heart.gif[/img], 3[img]/images/graemlins/diamond.gif[/img], 9[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(5 players)</font>
SB checks, <font color="#CC3333">BB bets</font>, UTG+1 folds, MP3 calls, <font color="#CC3333">Hero raises</font>, SB folds, <font color="#CC3333">BB 3-bets</font>, MP3 folds, <font color="#CC3333">Hero caps</font>, BB calls.
Turn: (10.20 BB) K[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">BB bets</font>, <font color="#CC3333">Hero raises</font>, <font color="#CC3333">BB 3-bets</font>, <font color="#CC3333">Hero caps</font>, BB calls.
River: (18.20 BB) T[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">BB bets</font>, <font color="#CC3333">Hero raises</font>, <font color="#CC3333">BB 3-bets</font>, <font color="#CC3333">Hero caps</font>, BB calls.
Final Pot: 26.20 BB
This hand seemed a lot more straightforward. Use my position relative to the maniac to try and isolate with him and just take my chances that the board didn't help him.
So I think I had the general idea of what to do but I was just a little confused on what his play did to the range of hands I could play.