I looked at the files you supplied in your support ticket and the problems you are having are due to using differant db column on the registration page and the login / emailPW page.
On the re3gistration you are not storing any values into the EmailAddress column, The email address is being stored in the UserName column.
On the Login page, you are using the EmailAddress column instead of the UserName column.
Also on the emailPW page, you are using the EmailAddress column, not the UserName column.
For the error message, you still have the login failure going to:
set the login failure to go to:
if you access the login page directly with that querystring:
you will see that the error message code is working.