If you are still missing either Pre-order or Deluxe Account Items, you may not have applied all of your available serial codes.
For players missing Deluxe Account items:
The code you registered may be a Pre-order only code, which gave you Head Start access, but not all of the retail perks.
You will need to contact your retailer to get your full Standard or Deluxe Edition code, and apply that to your account in order to reap the full benefits of buying the game.
Once you have applied your full retail code, you will have access to all of your account perks.
For players missing Pre-order Items (like the Rocket House!)
This is a bit more rare, but we have heard that some retailers gave out the full Standard or Deluxe Edition codes right away, rather than giving you a Pre-order code for Head Start access, and having you pick up your full code later.
It may seem a bit silly, but that Pre-order code is actually really important! It holds the key to any Pre-order exclusive items, and needs to be added, even if you've already applied your full game code.