Apparently Target had meant to post the carseat at $42.99 off, not $42.99. So my order has been canceled. It did seem too good to be true.
I know mistakes happen, but I didn't even get an e-mail about the cancellation. My order was just canceled when I went to check the status. Now that is poor customer service.
edited to add:
I did finally recieve and e-mail from Target about the cancellation at 6:45pm. I do feel however, they should have included a 10% off my next purchase coupon, or something. It wasn't a very sincere apology, in my opinion.