Server remembering old rewrite rules, even when I remove htaccess

It might be worth to check whether the caching happens on the client and not server-side. Firefox will cache any 301 (PERMANLTY moved)-redirecteds for a few days. Use 302 (temporary) redirect. To fix "old targets" you can set up an html page redirecting to another domain (e.g. without www) etc. to prevent firefox from using its cache.

Is there a place with cached rules? I've never had this problem before!

(usually) not server-side, but client / browser-side; try to cache-clean your browser as well

EDIT 1

suggestion: move out the .htaccess - file from your docroot. when there are still rewrite-rules active, they must be somwhere: either in your docroot or in <virtualserver> - config. to disable htaccess for your docroot, add the following to your server-config:

<virtualHost>
    ...
    DocumentRoot /some/path
    ...

    <Directory /some/path>

        AllowOverride None

    </Directory>

</VirtualHost>  

• restart apache

If your are sure your dont have any RewriteRule in your Server-Config AND with teh snippet above still get rewrites, i smell fish