What is the correct play, here?

[AaronO]

$2 no limit MTT
40 players left, 20 places pay
I have around T7500 and am just above average stack
Blinds T200/T400
I'm in MP, with 2 limpers and find AK [img]/images/graemlins/spade.gif[/img]
I raise to T2000
folded to UTG +1 who calls my raise
Flop
9-6-3 rainbow
UTG checks
I bet T2400
UTG check raises all in, and has me covered
Fold or call and why?
This hand has been bugging me greatly, so any thoughts are extremely appreciated.