KK against super passive villan's PFR and Cap. Mistake?

[A_K]

Over 100 hands villan is 36/1/.5. That's right, he raised once in 100 hands. My only notes on him are that he will call down with anything -- I didn't see him limp any big pocket pairs. For a fleeting moment I almost folded pre-flop. Was my play appropriate here?

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

Preflop: Hero is SB with K[img]/images/graemlins/diamond.gif[/img], K[img]/images/graemlins/heart.gif[/img].
<font color="#666666">1 fold</font>, UTG+1 calls, <font color="#CC3333">UTG+2 raises</font>, <font color="#666666">1 fold</font>, MP2 calls, <font color="#666666">3 folds</font>, <font color="#CC3333">Hero 3-bets</font>, <font color="#666666">1 fold</font>, UTG+1 calls, <font color="#CC3333">UTG+2 caps</font>, MP2 calls, Hero calls, UTG+1 calls.

Flop: (17 SB) 8[img]/images/graemlins/heart.gif[/img], 7[img]/images/graemlins/spade.gif[/img], 9[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(4 players)</font>
Hero checks, UTG+1 checks, <font color="#CC3333">UTG+2 bets</font>, MP2 folds, <font color="#CC3333">Hero raises</font>, UTG+1 calls, UTG+2 calls.

Turn: (11.50 BB) 8[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">Hero bets</font>, UTG+1 calls, <font color="#CC3333">UTG+2 raises</font>, Hero calls, UTG+1 calls.

This was really bad news. Passive guy checkraises after smoothcalling my flop checkraise. Do you find a fold here? UTG+1 probably has a LOT of outs against us, and at best we're chopping with UTG+2s KK.

River: (17.50 BB) 7[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(3 players)</font>
Hero checks, UTG+1 checks, <font color="#CC3333">UTG+2 bets</font>, Hero calls, UTG+1 folds.

Final Pot: 19.50 BB

EDIT: Don't mistake this for a bad beat post. Its not. Really my question is would you ever fold a big pocket pair against someone who PFRs so infrequently? Automatically go into WA/WB mode?