Multiple facebook comment boxes on a single page?

The comments plugin doesn't have a xid paramter that I can see at: https://developers.facebook.com/docs/reference/plugins/comments

You need to specify a unique URL for each of the comment boxes

I have resolved multiple comments boxes issues for one page for my site. This is what worked for me:

When generating your FB code, you have to enter the "URL to comment on". For the first box, just enter the url. For second box I added mysite.com/#comments2. For third box I added mysite.com/#comments3. Etc, Etc. This should give you a separate comment box per URL. Hope this helps.