It also helps to know the player doing the raising. If you think he's loose, I'd re-raise him pre-flop and lead out post-flop whether I connected or not. If you think he's tight, you might be better off not calling a raise from him with AK, or at least look to hit top pair before you bet into him on the flop. You may be playing the hand too passively - calling the pre-flop raise and then checking when you miss, which is death no matter what you hold.