Two KK preflop decisions

This 1st one was against a 22/3.8 player.

Party Poker No-Limit Hold'em, $ BB (5 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

BB ($38.81)
UTG ($75.44)
MP ($14.85)
Hero ($55.20)
SB ($40.05)

Preflop: Hero is Button with K, K. SB posts a blind of $0.25.
UTG raises to $2.5, 1 fold, Hero raises to $9, 2 folds, UTG raises to $22, Hero...

This hand is against a very stupid aggro player...

Party Poker No-Limit Hold'em, $ Hero (5 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

Button ($67.08)
SB ($88.45)
Hero ($49.95)
UTG ($26.64)
MP ($150.96)

Preflop: Hero is BB with K, K. SB posts a blind of $0.25.
1 fold, MP calls $0.50, 2 folds, Hero raises to $2, MP raises to $6.82, Hero...

Hand 1: If those stats are over a decent sample size I'm inclined to fold (I've never folded KK prf before, but this might be the spot).

Hand 2: I think I call here and checkraise any decent flop. Pushing over is of course also an option, but I'm afraid you'll allow a lot of worse hands to fold.

Agreed with Robert, if the sample size is significant I think you might be able to fold, but it's still tough. People overplay QQ a lot, but some people play QQ really passive and just play it for set value.

With the second hand I'm just calling and check-raising most flops.