connection sharing with firestarter

[Pasha R]

I'm using firestarter to manage my firewall. I have to use pppoe for
my internet connection, so I use option "Start firewall on dial-out".
I'm also using option of Internet connection sharing, so my computer
acts as a router to enable other computer to access the internet.
Everything works well except that when firewall is started on
dial-out, ip forwarding is left disabled. I tweaked a firewall script
created by firestarter to print some additional information and I'm
absolutely sure that line 'echo 1 > /proc/sys/net/ipv4/ip_forward' is
executed. Also, if I manually restart firewall, it enables ip
forwarding. SElinux is set to permissive mode. What prevents
firestarter from enabling IP forwarding?

Thanks.