from error log:
[Sun Feb 03 13:21:13 2008] [error] File does not exist: /home/ra2war/public_html/500.shtml
[Sun Feb 03 13:21:13 2008] [error] SoftException in Application.cpp:238: File "/home/ra2war/public_html/phpBB3/index.php" is writeable by group
[Sun Feb 03 13:20:59 2008] [error] File does not exist: /home/ra2war/public_html/404.shtml
[Sun Feb 03 13:20:59 2008] [error] File does not exist: /home/ra2war/public_html/phpBB3/install/install.php
[Sun Feb 03 13:20:42 2008] [error] File does not exist: /home/ra2war/public_html/404.shtml, referer:
http://forums.x10hosting.com/scripts-3rd-party-apps/50195-phpbb3-install-issues.html
[Sun Feb 03 13:20:42 2008] [error] File does not exist: /home/ra2war/public_html/home, referer:
http://forums.x10hosting.com/scripts-3rd-party-apps/50195-phpbb3-install-issues.html
[Sun Feb 03 13:20:23 2008] [error] File does not exist: /home/ra2war/public_html/404.shtml
[Sun Feb 03 13:20:23 2008] [error] File does not exist: /home/ra2war/public_html/phpBB3/install/install.php
[Sun Feb 03 13:20:15 2008] [error] File does not exist: /home/ra2war/public_html/404.shtml
[Sun Feb 03 13:20:15 2008] [error] File does not exist: /home/ra2war/public_html/favicon.ico
[Sun Feb 03 13:20:14 2008] [error] File does not exist: /home/ra2war/public_html/404.shtml
[Sun Feb 03 13:20:14 2008] [error] File does not exist: /home/ra2war/public_html/favicon.ico
[Sun Feb 03 13:20:14 2008] [error] File does not exist: /home/ra2war/public_html/404.shtml
Edit:
chmod? you mean permissions? its 755