I think this is due to us having to monitor new accounts, because of an overwhelming amount of spammers trying to sign up to promote their websites (without success, I might add!). The change of email was probably enough to activate the alert to Admins, and as a security measure, also to deactivate the account, until it was re-approved by an Admin.
If any members have a similar problem, please email an Admin, and we will sort it out for you.