Hi,
you have those lines in the function user_profile_field_save:
if ( !isset( $_POST['ja_disable_user'] ) ) {
$disabled = 0;
} else {
$disabled = $_POST['ja_disable_user'];
}
update_user_meta( $user_id, 'ja_disable_user', $disabled );
This writes the contents of $_POST['ja_disable_user'] directly to the database. You should avoid this and rather change the else block to
} else {
$disabled = 1;
}