What is it you're trying to accomplish?
Do you want the Smoothwall as your primary router?
That can be done. See the trade-offs of different router-router configurations with FIOS here:
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Verizon FiOS FAQ »
What are the tradeoffs between the various router configurationssaid by cdweber83:Will two Routers working as routers cause any conflicts?
Double NAT as previously mentioned.
said by cdweber83:How do I know my Routing and Firewall is being handled by smoothwall and not bypassed to Verizons Router?
If the Smoothwall is behind the Actiontec (Actiontec LAN-to-Smoothwall WAN), Devices behind the Smoothwall are behind two firewalls. The Actiontec and the Smoothwall.
said by cdweber83:I have seen others bridge the routers and turn off DHCP on Verizons Router but that seems to make the STB for TV stop working...
Not if it's done correctly. See the above trade-offs link.