Various issues surrounding email validation, may or may not already be known:

1. If "Require Email Validation" is turned on, and you create a User via the Admin panel, an email is sent to that user to verify. However, the Admin Create User area does not populate the yaf_CheckMail table, so when the user clicks the verification link, that verification fails.

2. If "Require User Login" is turned on, a new user cannot access the email verification page - they are redirected to the Login page.

3. If a user attempts to log in BEFORE verifying their email address, they are told their userid/password is incorrect, rather than being told that their email address needs to be verified before they can log in.