Do you make this call?

[sciencebeagle]

I recently played this hand in a single table tourney the other night and wanted some feedback.

Blinds 300/600
Four handed

In the BB with 1800 in chips. SB has 1200, button is short stack with 800. You get dealt A [img]/images/graemlins/spade.gif[/img]3 [img]/images/graemlins/diamond.gif[/img]. UTG folds, Button limps, SB raises all in to 1200. SB is LAG who likes to steal, but has been quite for the last few hands and suddenly wakes up. Button is pot commited and will have to call. What would you do?