If you have installed the internet security suite then uninstall it and reinstall only the norton antivirus (NAV) bit. I have seen no end of problems with the people setting up the internet security bit incorrectly and messing up the dial-up and local area network. Also, prevent NAV from forcing a connection and looking for updates at startup (although you should make it a habit of keeping your virus definitions up-to-date). I don't want to sound patronising but have you followed the NAV setup documentation carefully or have you just shoved the CD in, said yes/next to everything and left it with the default settings?