Before I found shorewall, I fiddled with firestarter, but I couldn't get it to
work because I don't have X, let alone gnome.

I'm using Gentoo.

I removed firestarter and went with shorewall, which is working fine but now I get errors like this when I install new services:

# /etc/init.d/courier-authlib restart
* Caching service dependencies ...
* Service 'firestarter' already provided by
'firewall'!;
* Not adding service 'shorewall'...
* Starting courier-authlib: authdaemond ...


How can I get rid of this pesky extra firestarter business?

Try This;
if you see firestarter still there remove it

i have also had some problems with remnants of firestarter hanging around after uninstalling it

i am new to linux, so i have no idea whether my solution is wise, but:

i found a reference to firestarter.sh in /etc/dhclient-exit-hooks, i removed the line containing that reference (which happened to be the only line in the file) to leave an empty file

this has solved, at least some of my problems, now i just have to work out why i have to stop & then restart iptables before being able to access my lan