Unfortunately its not without some level of pain for people. The problem was that anyone could change their Public Email address in their profile with no validation that the email address actually belonged to them. The pain is that because people were abusing this by changing their email address, then leaving reader comments appearing to be someone else, we now have to send a new password to the PUBLIC email address if you change it.
Thus, if you change your PUBLIC email address your account will be locked until you receive the new password. Think carefully before changing your public email address and most DEFINITELY do not change it to an email address that is not your own, because that email address will receive the password to your diary.
We're sorry we have to introduce this Draconian measure, once again, as is so often the case here at DearDiary, one or maybe two people have spoiled it for the vast majority...