Huge overbets on 4 flush boards

[GooseHinson]

Lately I have found myself in the following situation quite often with donks.

Full Tilt Poker
No Limit Holdem Ring game
Blinds: $0.25/$0.50
5 players
Converter (http://www.neildewhurst.com/hand-converter)

Pre-flop: (5 players) Hero is BB with Q/images/graemlins/heart.gif 7/images/graemlins/spade.gif
3 folds, SB calls, Hero checks.

Flop: K/images/graemlins/diamond.gif 7/images/graemlins/heart.gif 5/images/graemlins/heart.gif ($1, 2 players)
SB checks, <font color="#cc0000">Hero bets $0.5</font>, SB calls.

Turn: K/images/graemlins/heart.gif ($2, 2 players)
SB checks, <font color="#cc0000">Hero bets $1</font>, SB calls.

River: 9/images/graemlins/heart.gif ($4, 2 players)
<font color="#cc0000">SB bets $9</font>, Hero ???

Results:
Final pot: $22

The board pairing isn't typical to the situation, so in this case we could argue for a fold. However, when a villain bets 2x pot on an unpaired 4 flush board, is it correct to call? Logical reasoning would say donks usually bet their obvious nuts small (for value), is this some typical advanced cash game play I'm not familiar with yet?

[Sir Winalot]

I would probably call here, but wouldn't make calling a habit in these situations.

[martijn]

most times I call here I see either a ace high flush or a fullhouse. I dont think many people do this with J high flush or worse.

[fsista]

I'm sorry to tell you, but you're the donk. Check flop (!!). Then you might bet turn. This river is totally opponent dependant. I think a fold is standard though.

[BombayBadboy]

[ QUOTE ]
I'm sorry to tell you, but you're the donk. Check flop (!!). Then you might bet turn. This river is totally opponent dependant. I think a fold is standard though.

[/ QUOTE ]

This is a HU blindbattle, betting that flop is fine.

As played, I'd fold the river w/o a read that he is capable of this. You are getting terrible odds due to the overbet, give it up.