[CentOS] iptables local forwarding

Hi

I am trying to forward port 80 to 8080 locally using iptables with the 
following

/sbin/iptables -t nat -I PREROUTING -p tcp --dport 80 -j REDIRECT 
--to-port 8080

However this does not get put into the iptables configuration even after 
running iptables-save

Have i missed something along the way?

thanks