I already posted in the comment thread on http://we8u.com/facebook-comments/
After updating to FB comments v3.1.3 all historic comments are not displayed anymore. Furthermore now people cannot comment anymore at all, the whole comment box is completely missing. The only thing displayed is the Like-button. Using/Clicking this Like-button produces a clickjacking attack (reported by NoScript).
I was trying several other themes to make sure that not my theme (Akon) is the reason of the above mentioned problem. Means, problem still persists even if other themes (Wp3 ready themes) were selected.
Since the comments are displayed properly on the dashboard of wp-admin, it's also 100% sure that the correct XID is used and that no Facebook related error (such as data loss) occured.
I was using several different web browsers to make sure if it's a browser problem. FF, IE as well as Opera confirm the above mentioned problem. Only when using Dolphin HD on my smart phone, then the comments are displayed as well as the comment box etc.
Please help to get rid of this bug...