I posted this question from my account two days ago. Now suddenly, I saw I don't have an account any longer. I tried to log in and Overflow created a new account. Can someone please shed some light on what happened? I want to get my old account back.
Please note that my MSE account is still unharmed, and so are all other accounts on other StackExchange sites. However, MathOverflow just seems to have vanished into thin air.