Q: Since the latest update to my first generation iPhone software to 2.1 I get a nag screen when I update an application telling me that “This discounted price is only available to customers who own a previous version of this item. To purchase this item at the full price, click OK.” This happens with all updates even if they are free apps. Any thoughts?
A: The most common cause for this error message is that you are not logged in with the iTunes Store account that was actually used to purchase/download the app in the first place.
When you update applications via iTunes or the iPhone App Store, the list of eligible updates is generated based on the applications that are physically on your computer, regardless of which iTunes Store account they were purchased with. When you go to actually perform the update on the application, the list of applications is checked against the purchase history for whatever iTunes Store account your are currently logged in to. If you did not previously purchase the application using that particular iTunes Store account, then you will not be eligible to update that particular application, since iTunes cannot find a record of you actually owning that particular app.
If you are having this problem in iTunes itself and have more than one iTunes Store account, simply ensure that you are logged in with the iTunes Store account that was used to purchase the app initially. You can check which account was used for the application simply by going to the iTunes “Applications” section and choosing File, Get Info in the same way you would for a music track. The “Summary” tab will identify the iTunes Store account that was used to purchase that particular track:
For the iPhone, you will need to sign in to the proper account on your main iTunes computer, and then synchronize the iPhone to update the account information on the device. The iPhone itself does not provide a means to switch iTunes Store accounts directly on the device—it simply inherits the account settings from your main iTunes library.
If you are certain that you are logged in to the correct iTunes Store account and are still having this problem, then there may be a problem with your iTunes Store account itself or purchase history. In this case, you will need to contact iTunes Store Customer Service for assistance.