iptables has amnesia :-)

[Don Russell]

Twice now, I've applied new rules using iptables -I... to accept 
specific traffic, and each time those rules "disappeared" a little while 
later...

I don't see anything in "man iptables" like "... and don't you forget it!"
(Of course maybe I missed it...)

This is FC7.... using the cli iptables commands from root.... I also 
used webmin with the same effect.

Why are the new rules not remembered?

Thanks