One of our daily chores is checking new members who have registered and are Awaiting Confirmation by email to complete their registration. They can log in, but can't post until they are fully registered. If they don't complete it within a week or so, we assume that they're possible spammers and delete them.
Strangely, we've noticed some long-time members have suddenly been changed to Awaiting Confirmation for no apparent reason. At least one member changed his email address, which may have triggered the glitch. Of course, as soon as we find someone has been affected, we correct the problem and once we can definitely pin down the cause, we'll try to get it corrected.
So, if you suddenly find yourself unable to post or have other concerns, please send us an email at firstname.lastname@example.org