Postgresql remote connection not openning necessary ports

I bought a VPS from DigitalOcean with applications Rails+Unicorn+Nginx. I installed Postgresql 9.1 and trying to accept remote connections from that. I read all of the solutions/problems about it (Googled much) and did exactly. The problem is the following:

psql: could not connect to server: Connection refused Is the server running on host "xxx.xxx.xxx.xxx" and accepting TCP/IP connections on port 5432?

I edited the postgresql.conf file with listen_addresses=‘*’ I edited the pg_hba.conf file and added host all all 0.0.0.0/0 md5 I restarted postgresql service and even the VPS however still I cannot connected to the database. So I tried to check the server’s listening ports:

netstat -an | grep 5432
tcp        0      0 127.0.0.1:5432          0.0.0.0:*               LISTEN     
unix  2      [ ACC ]     STREAM     LISTENING     8356     /tmp/.s.PGSQL.5432

and then I nmap’ed the server from different machine:

Not shown: 996 closed ports
PORT    STATE SERVICE
21/tcp  open  ftp
22/tcp  open  ssh
80/tcp  open  http
554/tcp open  rtsp

But still I cannot understand why postgresql not serving at the port 5432 after the configurations. I thought it might be caused by iptables. So that I add the following rules:

iptables -A INPUT -p tcp -m tcp --dport 5432 -j ACCEPT
iptables -A OUTPUT -p tcp -m tcp --dport 5432 -j ACCEPT

Still no work. Need advice.

Thanks.