OneNote in app purchase fails

I have an iPad 1 and I had to reinstall Microsoft OneNote. Since the iPad 1 can only update to iOS 5.1.1, I had to download OneNote 1.3. I had previously made the in app purchase to updgrade to more than 500 notes. I tapped "upgrade" to reauthorize my in app purchase and I get the message, "Cannot Connect to iTunes Store."