@deraleks: I can confirm this issue as well (Social v2.11, WP v3.9.1).
I think the issue may have to do with Facebook depreciating API v1.0 in favor of v2.0.
Anyway, it looks like the
aggregate_by_api function (in lib/social/service/facebook.php) doesn't pass an explicit limit function, which means that Facebook defaults to a limit of 25 (http://stackoverflow.com/questions/14876105/the-limit-of-facebooks-graph-api-limit-parameter
). It also doesn't look like the aggregation function does any paging for comments (there is some paging support for "Likes")
For posts where there are more than 25 comments, there is a "paging" and "next" field that should be followed:
Adding 'limit'=>'100' to the end of the array in line 255 of lib/social/service/facebook.php seems to provide an interim solution (at least up to 100 comments):
$request = $this->request($account, $broadcasted_id.'/comments', array('filter' => 'stream', 'fields' => 'parent,message,from,created_time,can_comment', 'limit'=>'100'));