iptables problems

[Arangel Angov]

I started having this problem with iptables a while ago. It seems that I 
can't start/stop iptables manually through the terminal. Only way I can 
control iptables is thru system-config-securitylevel. This used to work 
fine with default FC3 installation and I don't remember when exactly it 
started giving me a hard time. When I do "rpm -e 
system-config-securitylevel system-config-securitylevel-tui" I can 
start/stop iptables manually again, but when the packages are installed 
I can't do nothing from the terminal. It also gives me an error in 
System Settings > Server Settings > Services when I try to start or stop 
the service. It says smth like "Service couldnt start, error:" and thats 
it.
Another thing: I can't add firewall rules manually when I have only 
iptables installed (without system-config-securitylevel).

For example I want to use NAT so I can get Internet to my laptop and 
"iptables -t nat -A POSTROUTING -o ppp0 -j MASQUERADE" is just not added 
to the table of rules.

Anyone has any ideas, or should I visit bugzilla for this one?

Thanks,

Arangel