Simply unsubscribe from the emails you receive for this new email address (there is a "unsubscribe" link in the email).

Also, please use the "forgot password"  to recover the password of you old account.

I accidentally created a new account too by entering another email I use.  I was quite confused when I was instantly signed up with a new account.  There should  be a separate process for logging in existing users and new users signing up.

Hi Gordo,

Please send me your old email id so I can activate it and also send me your new email id so I can deactivate it.

My old account works and I was able to deactivate the erroneously created one.

My observation is that it is far too easy to create a new account by just typing an email and password.  When I typed in a different email I use by accident and my password, a new account was created with all the default information.  At first I thought there was an error at the server and I lost my account information.  It took me a bit to realize what I had done and was able to log back in under my correct account information.

Perhaps you should include some sort of confirmation such as "are you sure you want to create a new account" or simply have the sign-up process separate from the sign-on.