What did I do wrong with KK?

[B1GF1SHY]

Played this hand last night. Opponent was very tricky, liked to slowplay some hands and was quite a maniac. What did I do wrong? I wasn't quite sure if he had the J because he mixed it up a lot. If he didn't then that A on the river really *bleep*ed me up.

Party Poker Pot-Limit Hold'em, $4 (10 handed)

saw flop|<font color="C00000">saw showdown</font>

CO ($531.6)
Button ($195)
SB ($444.5)
Hero ($461)
UTG ($190)
UTG+1 ($211)
UTG+2 ($780.8)
MP1 ($670.02)
MP2 ($201.5)
MP3 ($252)

Preflop: Hero is BB with K[img]/images/graemlins/diamond.gif[/img], K[img]/images/graemlins/spade.gif[/img]. SB posts a blind of $2.
UTG folds, UTG+1 folds, UTG+2 folds, MP1 folds, MP2 folds, MP3 folds, CO calls $4, Button calls $4, SB (poster) completes, <font color="CC3333">Hero raises to $16</font>, CO folds, Button folds, SB calls $12.

Flop: ($40) J[img]/images/graemlins/heart.gif[/img], 8[img]/images/graemlins/spade.gif[/img], J[img]/images/graemlins/diamond.gif[/img] <font color="blue">(2 players)</font>
<font color="CC3333">SB bets $12</font>, <font color="CC3333">Hero raises to $32</font>, SB calls $20.

Turn: ($104) 4[img]/images/graemlins/heart.gif[/img] <font color="blue">(2 players)</font>
<font color="CC3333">SB bets $75</font>, Hero calls $75.

River: ($254) A[img]/images/graemlins/spade.gif[/img] <font color="blue">(2 players)</font>
<font color="CC3333">SB bets $150</font>, Hero folds.

Final Pot: $404
<font color="green">Main Pot: $254, won by SB.</font>
<font color="green">Pot 2: $150, returned to SB.</font>