You must be having a "Alias /manual ..." in your httpd.conf which is
overriding your virtual host settings. This is why your apache server is
trying to serve manual/en from /usr/web/htdocs/manual/en/ instead of a
path relative to your document root.
And this is why we have this as a troubleshooting entry for a long time now at
http://php.net/mirroring
| If you find that the manuals are listed on the documentation page,
| but all of the links open up a search page, you probably have an
| Apache /manual/ alias in effect. Remove that alias, restart
| Apache, and the manuals will be showing up.
Goba