The first account I create for this site was at about last year, logining with firefox account. I post some ideas and comments with my first account.
After a long while, i forgot this thing and loging with github, created the second account; but i rememberd my first account later.
I wanted to sign out and re-login with my first account, mozilla connect bypassed the login page and auto logined with my second account. The same thing happened even after i clean all cache and cookies and re-login with "Auto login is disabled".