Maybe you could try adding the --l7dir /etc/l7-protocols/protocols option to the iptables calls in addition to using the CUSTOMPREROUTING chain instead of the PREROUTING chain. Add the following line after the flush commands for the other custom chains in /etc/rc.d/rc.local:
[code:1]/sbin/iptables -F CUSTOMPREROUTING[/code:1]
Then do a reboot.
The purpose of using the CUSTOM* chains and the associated flush commands is that any changes to rc.local can be updated simply by running:
[code:1]/etc/rc.d/rc.local[/code:1]
