That's exactly why I advised Danny to purge and reinstall the package, because the default install must work with a working postgresql installation (at least with the postgresql debian package, which I guess he is using).
Once it works, changing the config to point to port 80 is simple:
1- Set the RUN_DAEMON var to "no" in /etc/default/aolserver4
2- Set the AOL_PORT (and AOL_ADDRESS, if you want) var to "80" in /etc/aolserver4/conf.d/openacs.sh
3- Restart aolservers with # /etc/init.d/aolserver4 restart