[問題][外掛]版面管理時出現錯誤訊息

[anson1983]

●架設主機作業系統：win xp pro
●快速架站程式：無\r
●上網方式：ADSL HINET
●安裝的程式：apache 1.3.29 +PHP4.3.2+MySQL4.0.15
●出現錯誤:
安裝完Admin Userlist 1.6.1跟Attachment Mod Version 2.3.9後
版面管理時出現以下錯誤訊息\r
Warning: Cannot modify header information - headers already sent by (output started at c:\web\www\phpbb2\modcp.php:1) in c:\web\www\phpbb2\includes\sessions.php on line 293

Warning: Cannot modify header information - headers already sent by (output started at c:\web\www\phpbb2\modcp.php:1) in c:\web\www\phpbb2\includes\sessions.php on line 294
以上兩種偶爾發生...

Warning: Cannot modify header information - headers already sent by (output started at c:\web\www\phpbb2\modcp.php:1) in c:\web\www\phpbb2\includes\page_header.php on line 474

Warning: Cannot modify header information - headers already sent by (output started at c:\web\www\phpbb2\modcp.php:1) in c:\web\www\phpbb2\includes\page_header.php on line 476

Warning: Cannot modify header information - headers already sent by (output started at c:\web\www\phpbb2\modcp.php:1) in c:\web\www\phpbb2\includes\page_header.php on line 477
以上三種是只要執行版面管理就會出現\r

雖然有這錯誤訊息,
但一切使用接正常,
這是什麼原因??