iPhone says “The Apple Id you entered Couldn't be found or was incorrect. Please try again.”

Question

All of a sudden my iPhone 4 (iOS4.0.2) can no longer download apps. It says:

The Apple Id you entered Couldn't be found or was incorrect. Please try again.

I know for certain that the password is entered correctly. I have only 1 iTunes ID. I downloaded an app successfully this morning, over 3G. But now I consistently get this message when I try to download any app! I'm still on 3G with adequate signal strength.

I've quit all running apps, I've restarted (twice) and even a hard reset. But still I get this message. I've also noticed that the battery level is falling rapidly (1% every 2 min's) despite no other running apps/wifi/Bluetooth, so it must be doing some heavy 3G traffic.

What's up? How can I solve this? Preferably without involving my PC at home because I will be travelling for the next few days...

My exact steps:

• tap on App Store
• find any (free) app, tap on Install. Itunes closes, I see a white placeholder app icon labeled Waiting..., and I'm asked my iTunes password.
• I enter the correct password and tap OK.
• The white placeholder icon is still Waiting... for a long time.
• After ~5min's the correct app icon is show, but still labeled Waiting....
• After additionally ~5min's there's a new popup with the text The Apple Id you entered Couldn't be found or was incorrect. Please try again. and buttons Cancel and Retry.

Note: I've seen entries like this one but they are based on working on a Macintosh. I'm at work so I hope for a mobile solution.

Answer 1

This might have been some kind of outage in the App Store, because it works now, following the exact same steps with the exact same conditions (location, network, etc.).