Doesn't work with Metropolis theme

Q: Did you modify the theme?
A: I already tried a fresh installation of the theme, and it still didn't work. The other themes works fine with this extension, but we already customize the theme for a month and it's rolled out, but i wanted to change the comment box with something else, so I found this extension.

Q: What browser do you use?
A: FF 3.6.24, which I don't want to upgrade for several reasons. But I don't think it's a browser issue, since I got the same result with newest Chrome, and other themes (default themes: bluemarine, chameleon, engines, garland, pushbutton) work with this.

Q: Can you explain how it doesn't work?
A: I installed the module, turned it on, but it doesn't show up where it supposed to. Curious thing is, if I look at the source file, the facebook comment is there, above the comment section (btw isn't this extension supposed to "hijack" the comment module? http://drupal.org/node/1126028 Do I need to turn off the comment manually?). I can't find the solution for this...

PS: if it helps, our previous theme: internet_services (http://drupal.org/project/internet_services), also didn't work with this extension, but I haven't try a fresh installation of that theme. Also, I used Facebookshare module http://drupal.org/project/facebookshare