1) You have just registered a new account. All new accounts require confirmation before message posting is allowed.
2) You have recently modified your profile. Whenever you make changes to your profile, you will be asked to confirm it again.
3) The forum administrator has received a notification that your email address is invalid or not working properly. Whenever the discussion board tries to send a message notification to the email address you have in your profile, it checks to see if that email was delivered properly. If the email cannot be delivered properly for any reason, the administrator is notified. If it appears to the administrator that your email account is no longer working, your account will be reset so it requires confirmation. If you believe this is the case, please update your profile with a working email address.