Thanks !! We fixed it for every template we have, thanks!
Now, a forummember still claims he cannot edit or quote. He has the permissions though. What else besides language folders can cause this?
Simplest ideas first, make sure the user has cleared his browser cache by hitting ctrl+F5 while viewing the topic. If it's just one user, it's probably a cache problem on his end.
It wouldn't hurt to purge the forum cache, refresh your templates and imagesets, but if you can see the changes yourself that probably isn't the issue.