[TYPO3-english] realURL defaultToHTMLsuffixOnPrev isn't recognized

[typo3 at wehe-online.de]

Hello,
I use realURL on our corporate website and moved to a new server.
The menu generates links like http://www.domain.de/media-newsroom.html
but a click on this link throws me a 404 error. When I manually open
http://www.domain.de/media-newsroom it loads
http://www.domain.de/media-newsroom/ and everything works fine.

Here is the fileName part from my realurl_conf.php:
'fileName' => array (
    'defaultToHTMLsuffixOnPrev' => 1,
    'acceptHTMLsuffix' => 1,
    'index' => array(
        'robots.txt' => array(
            'keyValues' => array(
                'type' => 201
            ),
        ),
        'pdf.html' => array(
            'keyValues' => array(
                 'type' => 123
             ),
        ),
    ),
),

Any suggestions?

Jan