HU dilemma...

PokerStars $30+3 No-Limit Hold'em SnG, Big Blind is t200 (2 handed)

2nd hand HU. opp is erractic. Even with a full table, he has been limping into lots of pots, even with a big stack with a whole array of poo (62o, K5o etc). Calls a lot of bets with nothing/ultra marginal holdings and likes to min-bet a lot when checked to.

Staresy (t9155)
BB (t4345)

Preflop: Staresy is Button with Khttp://www.flopturnriver.com/phpBB2/...miles/club.gif, Khttp://www.flopturnriver.com/phpBB2/...iles/spade.gif.
Staresy raises to t600, BB calls t400.

Flop: (t1200) 5http://www.flopturnriver.com/phpBB2/...iles/heart.gif, Thttp://www.flopturnriver.com/phpBB2/...miles/club.gif, Thttp://www.flopturnriver.com/phpBB2/...iles/spade.gif (2 players)
BB checks, Staresy bets t700, BB calls t700.

Turn: (t2600) 7http://www.flopturnriver.com/phpBB2/...miles/club.gif (2 players)
BB bets t1800, Staresy .....

Allin.

Can you really fold KK here?

He check called, then got himself pot commited. Is he capable of doing it with air? An underpair? You mention a lot of reads about his preflop. What about postflop? Is he very aggressive? Usually passive?
From your reads its hard to put him on a hand. He could have an underpair like 88/99, an overpair like JJ/QQ I think is unlikely, any Tx, or 75 for that matter.
The bet makes me think you're beat, though givememyleg is right - I don't know if I can actually fold KK here.

I'm not folding here. With 2600 in the pot, he bets out 1800 and has 1200 behind. So I'm looking at it as calling 3000 into a 5600 pot. Almost 2 to 1 on your money. His line is a little scary, but there are too many hands he could do this with other than a 10 or boat for me to fold KK heads up. This is the type of fold that I only make with a great read, usually in live play- even then, the betting pattern alone probably wouldn't convince me to fold.