Hello!

The user_contactmethods you have for Facebook and Twitter in the DT – Social informations section in the user’s admin profile is unfortunately named identically as those added by WordPress SEO. So a change in one overwrites the other.

Since WP SEO is using those fields for some pretty advanced SEO stuff, while yours is used mainly for display in the authors bio (I guess), it would be nice if you could namespace your fields with more unique names, perhaps something like this:

$user_contact_method['dt_twitter'] = __( 'Twitter Username', 'text_domain' );