When changing password

When your password is expired or to expire, continuum redirect you to the change password page
Enter your current password (e.g pass9) , then enter the new password as one that you have used before (e.g pass1)
Continuum display a message saying that you can't reuse a password you have already used, but it DOES change the password
If you want to change the password to something else, you would need to use current password as the password that was considered invalid (e.g pass1)

This is reproducible in the Apache continuum environment (vmbuild.apache.org)