I tried this also in the virtual host section but I do not want to make
it more difficult so I moved it into the .htaccess file.

Problem:
I have two domains www.mark-fink.de and www.mark-fink.com. Now I want to
enforce the use of www.mark-fink.de all others (mark-fink.com ...)
should be directed to this url. I set the aliases in the virtual host I
use section (file since I use debian sarge).

the .htaccess file looks like this:
# Force usage of www.mark-fink.de
RewriteCond %{HTTP_HOST} !^www\.mark-fink\.de [NC]
RewriteCond %{HTTP_HOST} !^$
RewriteRule ^/(.*) http://www.mark-fink.de/$1 [L,R]

# enable url rewriting for Typo3 RealURL extension
RewriteEngine On
RewriteRule ^typo3$ - [L]
RewriteRule ^typo3/.*$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-l
RewriteRule .* index.php

(the typo3 realurl works fine)
I configured the cannonical hostname section according to the apache
manual for version 1. Is something discontinued or altered?

Any ideas?

Regards,
Mark