Pokerstars $27 9-handed: strange BB call by a regular

[SongheJe]

So.. what should do ? Never push a regular ?
I'm living a semi-tilt period because my winning on allins are really below expectation, but I was able not to impact the game (not a rigged-rigged crying but a serious post-game analysis with a software to analize EV from hand history and effective results)
So it seems I can't deal against 'bad play'... another example:

PokerStars No-Limit Hold'em Tourney, Big Blind is t200 (5 handed) Poker Stars Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

BB (t1725)
UTG (t2240)
MP (t3545)
Button (t4770)
Hero (t1220)

Preflop: Hero is SB with 2[img]/images/graemlins/heart.gif[/img], 6[img]/images/graemlins/diamond.gif[/img].
<font color="#666666">3 folds</font>, <font color="#CC3333">Hero raises to t1220</font>, BB calls t1020.

Flop: (t2440) T[img]/images/graemlins/heart.gif[/img], K[img]/images/graemlins/diamond.gif[/img], 7[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>

Turn: (t2440) 3[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>

River: (t2440) 6[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>

Final Pot: t2440

It's another winning regular with Q5s on the BB... Of course they were diamonds..
I really should do calls like that to survive ?