Your account was disabled (by nulling the password field) because yours was one of the passwords leaked in the "perlmonks hack" of May, 2009. In reviewing the list of compromised accounts, I discovered about a dozen which still had their passwords unchanged since the leak. Yours was one. Seems you ignored all the admonitions to change your password at the time!

I'll re-enable your account, by filling in a temporary password. You should then use What's my password? to retrieve it; and then, once you've logged in, set it to something new. And please exercise better password hygiene. :-)