Thanks for your answer vipsoft, I looked in the source code too and saw that some lines are doubled, the var pkBaseUrl section shows up again, copy and paste from the piwik adminpanel into notepad++ with strgC & strgV, the index.php shows exactly the code I pasted in. Uploaded with filezilla, downloaded again, looks still fine. Then watching the source code in firefox, code is messed up. Possible conflict with the scripts of the rockettheme template?
there’s a component for joomla named “sh404SEF”, that generates user friendly urls, in it’s options you can mark all outgoing links with a little symbol. This option messes the code up. Just disabled it and everything is fine again.
edit: FF & IE are still fine, only opera 9.64 shows still a “Analytics software” link. I must go deeper into joomla.