Honestly, I think you should be raising AA here 100% of the time. I also think that you should be raising a lot of other hands here. If you do that, then it won't be obvious you have AA.
I agree with both Harrington and Sklansky that you shouldn't ever be 100% that you would never limp with aces or check aces in the BB, because it is a tell that you don't have aces when you limp or check in the future. But I'd definitely agree with raising here the vast majority of the time.
As played, you should definitely not shut down--but as others said, don't play for a big pot. Little pots for little hands, as the saying goes, and at this point you've got a little hand. One pair as you said, but it's still a pretty good pair, so not the same as no hand at all.
ETA: I believe in the section of HoH where Harrington talks about not always raising with aces, he also said it was a theoretical mistake ever to slowplay them preflop (backing up Zach's instinct). But against observant opponents (and considering online people can easily take notes on you and review hand histories) you do have to just occasionally mix things up. It can also potentially discombobulate players who lose a pot to you this way, or even the rest of the table (especially helpful in a STT). Every time you limp or check into a flop, your opponents may be wary of you--and that's got to be to your advantage since statistically most of the time you will not have much if anything.