App Store :: Purchase Getting Stuck At Security Questions?

This has happened over the past few days. I've attempted to make new purchases both in the App Store and on iTunes. I'm queried for my Apple ID, then I'm asked to enter three new security questions and answers. When I complete this step, I receive a message that the App Store (or iTunes, depending on where I am) is "temporarily unable to process" my request and to try later. I've even reset my Apple ID password, logged out, logged back in, and attempted a purchase, but to no avail. I've run into the same problem attempting to purchase new apps on my iPhone and iPad as well. Updates to previously-purchased apps work, but not new purchases.