Cowboys facing open shove on flop

[robinmbuk]

Pacific Poker
No Limit Holdem Ring game
Blinds: $0.12/$0.25
6 players
Converter

Stack sizes:
UTG: $50.64
Hero: $25.75
CO: $17.56
Button: $20.26
SB: $30.04
BB (Villian - 45/18/1.2): $11.03

Pre-flop: (6 players) Hero is UTG+1 with K[img]/images/graemlins/club.gif[/img] K[img]/images/graemlins/diamond.gif[/img]
UTG folds, <font color="#cc0000">Hero raises to $1</font>, 3 folds, BB calls.

Flop: 4[img]/images/graemlins/heart.gif[/img] 2[img]/images/graemlins/diamond.gif[/img] 5[img]/images/graemlins/heart.gif[/img] ($2.12, 2 players)
<font color="#cc0000">BB is all-in $10.03</font>, Hero ?.

Villian bought in short rather than losing a big pot. I've only played one pot with villian where he sucked out to a turned flush draw vs me with less then 1/2 a psb left. He cheked when he hit then open shoved river.

My first thought when he shoved is and overpair (most of which I beat but he could play AA this way), some sort of combo draw or a set that is afraid I could draw to a flush. What One thing to consider is the last time he flopped a draw vs me when short he didn't shove. I didn't consider at the time that given his pf raise stats he prob raises most overpairs pf. One thing that sticks in my mind is why not c/r allin if he has a good hand like a set? Afraid I'll draw to a flush maybe?

Call/fold? Please explain your reasoning as I'm trying to learn.