Thanks to Nils Ally I had a little more work than expected :) he found a strange problem with myblog and our comment plugin for it. When the plugins "content - !joomlacomment" and "MyBlog - joomlacommentmyBlog" were both enabled, then the articles were loading the comments twice.
Now we are checking for the scope of the application in the compojoomcommentMyBlog plugin and if we are in myblog then we load the plugin, if not nothing is executed. This fixes the problem and all subscribed users can find the plugin in the download section.
The second problem was with the latest comment module. (Thanks to our user Juanje for reporting this yesterday) . When the module was published more than once on a site, then it was creating this fatal error:
Fatal error: Cannot redeclare class modCommentsHelper in .../helper on line 25.
I fixed this problem too and the new module is in the download section. Thank you for your support and sorry for the inconvenience!