Namenlos notified me that my dasBlog Autotrackback Feature does not work as is is expected to work. The problem was, that everytime you link to the front page of a weblog, dasBlog trackbacks the first article of the weblog.
The Specification says:
“Scan the page contents for embedded RDF. Pages can contain multiple instances of embedded RDF–clients should pick the block whose dc:identifier matches my_url.”