Fb likes button disappearing intermitently

Roxana,
The problem looks to be from the buttons that you're using. Whatever is adding those social buttons is loading the very old version of the Facebook Javascript library (all.js). That library was replaced almost 2 years ago by Facebook with the 'sdk.js' file that JFBConnect properly includes.

Both of those libraries from Facebook are not supposed to be loaded at the same time or conflicts will occur, like are happening on your site right now.

The file that is loading the old library (just search for all.js):
plugins/system/joomsharebarpro/joomsharebarpro/socialite/socialite_new.min.js

I'd recommend checking if there is a new version of that library or removing the code that's loading that older file from it. JFBConnect is already loading the proper one, so it's not necessary for that extension to do so.

I hope that helps,
Alex