$25 NL 6-max: KK meets horrible river card/villain shove

[floppy]

Thoughts? Bad fold? This is the first time I think I've ever folded an overpair (yes, I'm still learnin'):

Full Tilt Poker - No Limit Hold'em Cash Game - $0.10/$0.25 Blinds - 5 Players - (LegoPoker Hand History Converter)

SB: $29.25
BB: $36.70
UTG: $70.20
Hero (CO): $31.10
BTN: $9.40

Preflop: Hero is dealt K[img]/images/graemlins/spade.gif[/img] K[img]/images/graemlins/heart.gif[/img] (5 Players)
UTG folds, <font color="red">Hero raises to $0.85</font>, BTN calls $0.85, SB calls $0.75, BB calls $0.60

Flop: ($3.40) 6[img]/images/graemlins/club.gif[/img] Q[img]/images/graemlins/spade.gif[/img] 9[img]/images/graemlins/heart.gif[/img] (4 Players)
SB checks, BB checks, <font color="red">Hero bets $2.50</font>, BTN folds, SB calls $2.50, BB folds

Turn: ($8.40) 7[img]/images/graemlins/spade.gif[/img] (2 Players)
SB checks, <font color="red">Hero bets $7.00</font>, SB calls $7.00

River: ($22.40) T[img]/images/graemlins/spade.gif[/img] (2 Players)
<font color="red">SB bets all-in for $18.90</font>, Hero folds
Uncalled bet of $18.90 returned to SB

Pot Size: $22.40 ($1.10 Rake)