I’m having the same problem as allenzuk and mbobo. I know this is an old post, but this problem still persists. Anybody found a fix?
Ok well nobody answered lol but I figured it out. Not sure why changing what I did made me not able to log in.
But what I did to fix was just request a new password and that seemed to fix it. If you do not know what email you registered that account with then do this: go to your hosting account -> phpMyAdmin -> select your sites database -> wp_users. That should show you your username and what email its registered to.