Do you know what email address you used when you signed up?
You would use the email addy and password that you gave when you signed up, to log in the game. Try using your different email addys, with a password you use often. Or maybe you could use the "contact us" link at the very bottom of the vmk main page, but I think you would need to know what email address you used to be able to do that.
You can just register again, which of course means losing any 'stuff' you had collected with the old ID, but at least you could still play the game and start anew.
