I activated the Tiki-Cache, because I link a lot to external sites. To keep the links in the blog-posts intact 'forever', I decided to activate the cache-feature. The pages get cached, when you view a page with an external link in it. So at the moment you only got four 'updated' posts, because I only viewed the latest blog-posts. It might happen, that there will be more.
Sorry for the inconvenience!