[syslog-ng] Need help IPs are showing not the hostnames[ Pls reply ASAP]

Dear All I have recently rebuilt a machine "Cent OS 4.2 " I have added few ips in /etc/hosts file but I cant see hostnames in syslog web interface which cache feature is disabled and when fetch queries from mysql DB its not showing me logs with hostname but its not showing in syslog web interface and when I only include that ip from web interface it shows me empty pls suggest Thanks Z0mbie