'i am checking, but i ain't folding.'
you check and he puts you all in. Does this mean you call then?
yup!
why would you check call rather than push?
To pick off a bluff, if i push he doesnt play worse hands, i am just gifting him my stack with no other equity than what is in the pot. If you check then at least he will on occasion be putting some chips into the pot with the worst hand!
My applogies if I have missunderstood the meaning of your post but are you suggesting it's more profitable to check-call than it would be to raise on the off chance he might be bluffing? Flies in the face of most convetional poker wisdom, is there any way this can be prooved mathematicaly? Most profitable moves go against the grain but calling down in this situation apears to be the quick fire path the rack and ruin to me.
Logic dictates that Flushy is right on this one. (Gold may help me for saying that) and I like his thinking here (OK, Now I really am going to hell for suggesting Flushy thought this through

)
The check call will be more profitable then pushing is, if the player might bluff at it. Afteral, you will only get called by hands that are beating you BUT someone might bluf into the pot to pick it up with absolutely nothing.
If you have decided your chips will go in the middle here the check call isn't a bad idea...but only if you don't mind getting knocked out of a tourney with 2nd pair.
There is nothing in the first post to suggest he's an aggressive player just loose, the villian has won when he called with 85s so the two calls in this hand don't seem out of character for man who likes to pay to see if his draw will hit. He limps twice, couldn't he just be drawing to a hand, if he is why give him a free card by checking? If he had a hand bigger than you wouldn't he have raised at some point in the hand instead of just calling?
I've been caught out on hands like this in the past but I think it's my lack of observation at the table and so I make the wrong move, I'm still not convinced checking here is the right move when you have been taking the lead in this hand.
Just a hunch, the kind of player that flat calls KK on the button after a raise and also limps with trashy suited connectors tends to be capable of raising with draws.