Jeroen Wiert Pluimers has notified me in his comment on Google+ that the RSS feed for GExperts related posts doesn’t work. I apparently forgot a forward slash in the url:
correct:
http://blog.dummzeuch.de/category/gexperts/feed/
wrong:
http://blog.dummzeuch.de/category/gexpertsfeed/
It’s fixed now, sorry about that.