Cannot access an allowed website due to personal information being detected

I have registered my son to use the Doctor Who Monster Invasion website (www.doctorwhomi.com) but as he has to log in using his e-mail address he is blockd because personal information has been detected.  I do not want to disable the detection of personal information for obvious reasons but I do want him to access this allowed site.  I have added the website onto the allowed websites list but he still gets blocked at the login stage.  How do I overcome this?  Thanks, Alan.