I found a very pretty style for the K2 theme, called TrueBlue, so this blog looks a little bit different again. (Yes, you have to visit the website, if you read the blog via rss feed… 
) Furthermore, I installed Date-Stamp, a WordPress plugin by the same author as TrueBlue. But I am not yet quite sure, whether I really like Date-Stamp. If you have an opinion, drop me a comment…
Update: And I could finally activate successfully the AJAX navigation feature at the top. Try it know.
Looks nice