Rewrite FileInfo Bug/Prob: Plesk 11.5, Horde 5.1.5, PHP EPEL/REMI 5.4.25, Apa 2.2.15

[MarkusSc]

Hello,
I've a working Plesk installation with Horde Webmail (versions mentionned in title) on CentOS 6.5.
In the vhost configuration file horde.conf under /etc/httpd/conf/plesk.conf.d of "webmail.mydomain.tld" there is a directory entry for /usr/share/psa-horde to be run by the fcgi module:

<IfModule mod_fcgid.c>
        FcgidInitialEnv PP_CUSTOM_PHP_CGI_INDEX fastcgi
        FcgidInitialEnv PP_CUSTOM_PHP_INI "/etc/psa-webmail/horde/horde/php.ini"
        FcgidMaxRequestLen 134217728
        <Directory "/usr/share/psa-horde">
            <Files ~ (\.php$)>
                SetHandler fcgid-script
                FCGIWrapper /var/www/cgi-bin/cgi_wrapper/cgi_wrapper .php
                Options +ExecCGI
            </Files>

            SSLRequireSSL
            Order allow,deny
            Allow from all
        </Directory>
    </IfModule>

In this directory, there is a .htaccess file with the following content:

# IMPORTANT: DO NOT EDIT THIS FILE!
# It will be overwritten with any future upgrade.

Allow from all

<IfModule mod_rewrite.c>
    RewriteEngine On
    RewriteRule .* - [env=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
    RewriteCond   %{REQUEST_FILENAME}  !-d
    RewriteCond   %{REQUEST_FILENAME}  !-f
    RewriteRule ^(.*)$ rampage.php [QSA,L]
</IfModule>

This configuration leads to the problem that the short url, horde webmail system uses to write down a task for example /nag/t/save does not work. There are more short urls, which do not work either. At least the task system is unusable with these standard settings.
The .htaccess file is never executed, since in the horde.conf there is missing an AllowOverride FileInfo directive before </Directory>.
To get things to work, you have to delete the Allow from all from the .htaccess file, otherwise apache does not start.

Please, could you tell me what am I doing wrong, or put the changes into the standard, because after every change in the server configuration my changes are overwritten.

Thanks, Markus