Looking at my awstats graphs I found out that I had some not exepcted 404 pages (e.g. “/2008/12/programming-erlang/”). I checked it and it was obvious it was caused to the activation of Wordpress permalinks. After some investigation I realized the issues where caused by:
- missing .htaccess. Probably due to file permissions.
- Apache’s mod_rewrite module disabled.
- Apache’s Allow Override not enabled.
I guess I made all possible mistakes 
