Starting with 2.0-alpha4, this module added a check to see if a Facebook plug in was used on the page and only add the footer script if this was the case. We have one page where the only buttons used are inside a quick tab (from the Quick Tabs module) and in this situation, the check returns FALSE.
I got around this by having the menu hook set this global variable explicitly.
$_fb_script_init = TRUE;
I'm not sure exactly how the module works or if this edge scenario is even worth accounting for. We only use quick tabs and this module in a very limited way.
I wanted to leave this trail in case people ran into a similar issue and to bring it to attention in case someone has the time to work on it and felt it was important.
Thank you for the module!
End note: I have not tested the quick tabs / fb_social connection too thoroughly, but it makes sense that this was the cause since we aren't using any other system such as panels / panelizer.