Yes, mine is missing the apartment number, too. I noticed this while on the phone placing the order (the email sent really quickly) and when I asked about it was told the apt number was in the system on their end. I didn't trust the rep so I called back immediately afterward and the next rep saw what I was talking about and just said to call back two days prior to the estimated ship date (9/23 in my case) and confirm that the address was correct. I got the same story about them not being able to change it, at least not until it's about to ship. Also, worst case, you should be able to have them contact FedEx/UPS and have them make the change while it's in transit.
I think what might be happening is they're using a system that validates addresses and can't handle apt numbers. Annoying for sure.