Q: I purchased an iPod touch 32 GB as an upgrade from my iPod 3G. Since iTunes supports my whole family, I had to clear the authorizations to use my new iPod touch, which was no problem. However, shortly after, I received an iPod touch 64GB as a gift and sold the 32GB. I connected my new 64GB and sychronized it with my library. Now, many of the songs and audio books won’t play on the new iPod. I suspect it is because I’ve exceeded my authorization limit. I understand that I can only clear my authorizations once a year. How do I get my purchased songs and audio books to play on my new iPod? Thanks in advance.

– Ed

A: To be clear, you do not actually need to specifically authorize your iPod with the iTunes Store as it inherits its authorization automatically from your computer. The five authorization limit only applies to actual computers running iTunes, and not to iPod or iPhone devices. Apple permits you to have an unlimited number of iPod or iPhone devices authorized, provided they’re synced with one of your five authorized computers. When you transfer music from your iTunes library to your iPod, the authorization to play that music goes along with it, provided your computer has already been authorized.

If your computer is not authorized to play your purchased content, then iTunes will simply refuse to transfer those tracks onto the iPod in the first place, so you should not normally find yourself in a situation where the tracks are present but refuse to actually play.

You can troubleshoot this problem further by checking to make sure that your music actually plays on your computer in your iTunes library itself. If your computer is not authorized, iTunes should prompt you to enter your iTunes Store user name and password, after which it should authorize your computer for that particular iTunes Store account. Note that if you have purchased content in your library from more than one iTunes Store account, you will need to authorize each account separately.

Once you have confirmed that iTunes itself can play your purchased tracks, try synchronizing these tracks to your iPod again and see if they will then play properly on your device. Note that you may need to remove these tracks and resync them to your device to ensure that the authorization transfers properly.

If this fails, you can simply try restoring your iPod touch back to factory settings by connecting it to your computer and selecting the “Restore” option in iTunes. This will erase everything on your device and retransfer all of your content from your iTunes library, thus helping to ensure that any authorization information travels along with it.

It’s also worth noting that although you can have an unlimited number of iPods on a single iTunes Store account, you can only have content from a maximum of five different iTunes Store accounts stored on a given iPod. This is presumably to discourage people from visiting many of their friends and transferring purchased items manually from several different iTunes libraries.