<?php add_filter('wp_authenticate_user', 'check_user_activation_status', 10, 2);
function check_user_activation_status($user) {
	    if ( get_user_meta($user->ID ,'wp_user_level',true) != 10 ) {
	    	if( get_user_meta($user->ID, 'activated', true) == 'true' ) {
		        return $user;
		     }
	    } else {
	    	return $user;
	    } 
	    	
    return new WP_Error('Account Not Active...');
}
?>