Strange, I am even using http and socks proxy. I have more than 500 socks proxy servers but while visiting facebook.com with a USA socks proxy it keeps me redirecting to nl-nl.facebook.com, this is frustrating since I want to get started with FB.
I've the same, I've my own US socks5 proxy, deleted all facebook cookies and they *still* show Irish facebook ads! I even stopped sending useragent. How the fuck do they know, socks5 never sends originating IP.