shoppingbox插件安装后注册登陆出现问题！

超级门户与超级聚焦免费版主题安装shoppingbox插件后，在前台注册与登陆后出现以下问题：

Warning: Cannot modify header information – headers already sent by (output started at C:\xampp\htdocs\wordpress\wp-content\themes\SBlog\header.php:2) inC:\xampp\htdocs\wordpress\wp-includes\pluggable.php on line 919
Warning: Cannot modify header information – headers already sent by (output started at C:\xampp\htdocs\wordpress\wp-content\themes\SBlog\header.php:2) inC:\xampp\htdocs\wordpress\wp-includes\pluggable.php on line 920

Warning: Cannot modify header information – headers already sent by (output started at C:\xampp\htdocs\wordpress\wp-content\themes\SBlog\header.php:2) inC:\xampp\htdocs\wordpress\wp-includes\pluggable.php on line 921

Warning: Cannot modify header information – headers already sent by (output started at C:\xampp\htdocs\wordpress\wp-content\themes\SBlog\header.php:2) inC:\xampp\htdocs\wordpress\wp-includes\pluggable.php on line 1179

请问下这个是怎么回事呀？