Problem solved. This may be helpful to others, to avoid couple hours of wasted time. I have several twitter accounts. It turns out that when you go to twitter’s Application Management page, it silently uses whatever account happens to be open at the time. If that isn’t the account you registered with, then you get the “You don’t currently have any Twitter Apps.” reply. So, make sure you have the correct account open when you go to Application Management, and you’ll be ok.