Just a few days ago Google released a 2.0 version of its Authenticator app for iOS, but a bug made user's entries not show up and the company yanked it. Now v2.0.1 is back in the App Store, and it contains a fix for any two factor authentication users that downloaded the busted version. Based on the release notes, your old keys weren't cleared by the update, but they just weren't displaying. We tried it out on our iOS device that was blank after 2.0 and it worked as advertised, all accounts show up again. Although it's safe to upgrade there is one more issue: anyone who created replacement accounts already will have duplicates. To avoid that, your best bet is to rename any new entries before updating -- staying secure is fun and easy, isn't it?