Could not connect to remote socket

I have my postgresql DB on linux machine. and i have 2 windows clients for this DB.Things were working fine until this morning when client machines started giving error

Could not connect to server
Could not connect to remote socket

I have taken care of each thing like
1) Starting postmaster with -i option
2) pgaccess is running successfully
3) windows client machines can ping server.
4) windows client machines can access server's shared folders through samba services
5) pg_hba.conf file has 2 entries for my clients
6) i have uncommeted tcpip_socket=false in /var/lib/pgsql/data/postgresql.conf file and set it to true.

what else should i do to connect my windows clients machines with my linux server ??