[Plugin: Social] not broadcasting to Facebook

After authorizing my blog and its only user (me) with Twitter and Facebook, editing a post, publishing it, I tried to broadcast it thru Social Plugin. It worked for Twitter (plugin widget showed that and tweet appeared in my timeline, some replies collected as comments) but I couldn’t publish nothing to Facebook. I tried many times, changed FB privacy options to allow everybody publish in my wall, reauthorized Facebook account… but no way.