UPDATE: This is now happening on every computer in our home, so we no longer can enjoy any games that involve enhancements involving in-app purchases. And again, this hasn't been a problem for years of game-playing, it only happened when we performed the latest update.
Since there appears to be some confusion, I wanted to reiterate:
A) We attempt to make an in-app purchase.
B) We receive the message telling is that we already have purchased the item in question.
C) We KNOW we have already purchased that item, AND it does show up in our order history.
*The problem is that the items in question are meant to be purchased more than once, and we have never had a problem buying them more than once until now. I am NOT saying that we purchased something but are not getting it. I am saying that we are not allowed to make a purchase based on the fact that we have bought that item previously, when in fact that item should be allowed to be purchased more than once.
This is like going to Starbuck's to buy a coffee, and having them tell you that you can't buy a coffee because you already bought one yesterday!