I noticed some strange malfunctions, but ONLY when French is selected (at the bottom of the page), NOT with any of the other available languages:
1) Button "Show Voter" for a topic
=> doesn't show anything (but neighbor Button "Report" for menu seems OK)
2) Blue button "+" to add comment
=> doesn't do anything
3) Different results with Search field
=> Type "French" in the Search field
=> Only 1 answer from http://feedback.userecho.com/?lang=fr
=> Many answers from http://feedback.userecho.com/?lang=en
4) Less topics displayed in welcome page
e.g. http://feedback.inst.ag from your CLIENTS examples
=> No topics presented if French is selected
=> Many topics if any of the 9 other languages is selected
Maybe there are other "strange things" not reported here and only related to French...
It's surprising that it's focused on this language only.