simple (?) preflop question

[ethan]

In the middle of a party 5+1 right now, I wasn't quite sure what the proper play was preflop. The short stack limps UTG, I have 15BB and am covered by most everyone left to act. The big stacks haven't seemed too interested in gambling, though. I've been at the table 20 hands and stolen from them 4-5 times without incident. What do you do here?

Party Poker No-Limit Hold'em Tourney, Big Blind is t200 (10 handed)

saw flop|<font color="C00000">saw showdown</font>

BB (t8795)
UTG (t750)
UTG+1 (t3330)
UTG+2 (t4705)
MP1 (t1930)
MP2 (t5335)
Hero (t3046)
CO (t1950)
Button (t7665)
SB (t4272)

Preflop: Hero is MP3 with T[img]/images/graemlins/spade.gif[/img], A[img]/images/graemlins/heart.gif[/img].
UTG calls t200, UTG+1 folds, UTG+2 folds, MP1 folds, MP2 folds, <font color="CC3333">Hero...</font>