I am using FreeProxy 3.92 Build 1644 (download link http://www.handcraftedsoftware.org/index.php?page=4&action=category&cat_id=2 ), and it works ok. Try it locally on your system, with ProxyInfo class, like this:
if you are using HTTP Proxy type you have to put null for username and password
ProxyInfo proxy = new ProxyInfo(ProxyType.HTTP, “proxy.host”, proxy.port, null, null);
if you are using SOCKS4/5 proxy then your proxy info should be like this (you can put empty string “” for usename and password if your proxy is without authentication)
ProxyInfo proxy = new ProxyInfo(ProxyType.SOCKS4/ProxyType.SOCKS5, “proxy.host”, proxy.port, “username”, “password”);
Then put the proxy object in your ConnectionConfiguration:
ConnectionConfiguration connConf = new ConnectionConfiguration(“jabber.server”, jabber.port, “jabber.service”, proxy); (jabber.service is usually same as jabber.server)
I recomend first you read the help for FreeProxy, and with FreeProxy you can establish local HTTP/SOCKS4/SOCKS5 proxy server, and you can test it.