Okay, here's a bit of info that I forgot to include in my original post. I just came accross it recently. In a previous hand I get A9 of hearts on the button, villian in this hand (MrOstkaka) limps UTG, and I raise 4xBB, he calls, HU to the flop. Flop is Axx all spades. Flop goes check/check. Turn is a blank, he checks I bet $6 he calls. River is another blank he checks I bet $10 he calls and flips A5 clubs (actually it turned out to be a split pot).

Anyway, in response to your post miffed, here's what I think. It's always possible that he might have air and just be moving me off my hand, but based on my previous history with him and observing how he plays, he really didn't seem like the type of player to run these huge bluffs. Hard to explain, just a gut-instint type thing, but the possibility is always there. Also, this is kind of off-topic, but I think it might actually be a "leak" sometimes when we develop as poker players and move up in stakes that we don't see things for what they are on the surface. Sometimes when a guy bets big it means exactly that, that he has a big hand. I'm not saying this justifies my laydown here, just pointing out something that we may have forgotten from 25NL.

Also, keep in mind that raising the turn pot-commits you here. But more importantly, why raise the turn? If villian is behind, he is drawing very slim, so what's the point of raising. You think he calls a push w/99 here? Why not call and let him bluff the river if he does have air or extract a little more with a small value bet?

Why bet so much unless he thinks you get too attachedto big pairs? (do you?) or else why fire so big into a pot with the nuts.
Because he wants to play for stacks and a big pocket pair is the only reasonable hand that will pay off trips/boat here.