Hi Kristarella,
I changed them via the admin panel (options/permalinks > update structre). That works all fine.
I don`t think so….
These are the contents of my .htaccess file (chmod 666):
# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>
# END WordPress