Stars $6 Turbo - short stack ATs vs push

[JSampras1]

The guy who pushed didn't seem very good as he had limped several times at 100/200 and folded to bets. But i checked the hand history and he hadn't raised in a very long time. My stack is pretty small and i need to get some chips. Also he's pushing over the shortie limping. Is this a call or a fold here?

PokerStars Tournament, Big Blind is t200 (7 handed) Converter on pregopoker.com

UTG (t1755)
UTG+1 (t3500)
MP1 (t105)
CO (t1195)
Button (t975)
Hero (t1075)
BB (t4895)

Preflop: Hero is in SB with A[img]/images/graemlins/heart.gif[/img] T[img]/images/graemlins/heart.gif[/img]
<font color="gray">UTG folds</font>, <font color="gray">UTG+1 folds</font>, MP1 calls t105 (All-in), <font color="gray">CO folds</font>, <font color="red">Button raises to t975 (All-in)</font>, <font color="gray">Hero ???[/color