I'm the author of this plugin. Thanks for testing it.
Yeah, I forgot to instead the Chinese characters by English words. Now I remove them(instead by international version just as
_e('words'); and update the plugin to version 2.5.5. But I'm not sure is there any missing one. If you find one, just point it out here, thanks.
As the DEMO(It's a Chinese blog, but you can see what does the plugins look like and how does it work) showed, you don't need any more "QUOTER" or "THRESHOLD" or "AJAX COMMENTS" plugins . AJAX Comments-Reply takes all of them. Even more, they might be conflict with each other, because they do the same thing twice if you use both of them. So, just deactivate "Quoter", that's my suggestion.
Any comment, bug report and feature suggestion of this plugin are welcomed and appreciated.