However, if I search like this, many of the tagged articles show up - together with the tag.
Edit: When I am connected anonymously on another machine I can see the 11 questions. But as false, I don't. And: I do not have ignored tags...
Edit: Solved. I should have look at the result in more detail. However, the actual reason for this misunderstanding is the following:
As long, as I search for a single tag, I get the riders "info", "newest", "faq", "votes", "active", "unanswered".
But when I search for a tag plus a searchstring, I get the riders "relevance", "newest", "votes", "active".
So when I cross-checked, I got "better" results, because I now got the "relevance" rider in place of the "faq" rider.