gnubord4 디렉토리안에 있는 index.php건드리지않았는데 ㅠㅠ

http://도메인/gnuboard4/ 로 들어가면 메인화면은 제대로 작동하구
메인화면 제일위에

Warning: Cannot modify header information - headers already sent by (output started at /home/hosting_users/mobibugs/www/gnuboard4/_common.php:5) in /home/hosting_users/mobibugs/www/gnuboard4/head.sub.php on line 32

Warning: Cannot modify header information - headers already sent by (output started at /home/hosting_users/mobibugs/www/gnuboard4/_common.php:5) in /home/hosting_users/mobibugs/www/gnuboard4/head.sub.php on line 34

Warning: Cannot modify header information - headers already sent by (output started at /home/hosting_users/mobibugs/www/gnuboard4/_common.php:5) in /home/hosting_users/mobibugs/www/gnuboard4/head.sub.php on line 35

Warning: Cannot modify header information - headers already sent by (output started at /home/hosting_users/mobibugs/www/gnuboard4/_common.php:5) in /home/hosting_users/mobibugs/www/gnuboard4/head.sub.php on line 36

Warning: Cannot modify header information - headers already sent by (output started at /home/hosting_users/mobibugs/www/gnuboard4/_common.php:5) in /home/hosting_users/mobibugs/www/gnuboard4/head.sub.php on line 37

Warning: Cannot modify header information - headers already sent by (output started at /home/hosting_users/mobibugs/www/gnuboard4/_common.php:5) in /home/hosting_users/mobibugs/www/gnuboard4/head.sub.php on line 38

이런에러가 떠요 ㅠ 인덱스파일 따로 건드리지는 않았는데 에러가 뜨네요..
어떻게 없애나요 ㅠㅠ
고수님들 도와주세요~