Norton is a crummy product, both the antivirus and utilities portions of it. In my years of using a Mac running it has never caused a positive result.
When I had a virus, like 6 years ago, Norton anitvirus didn't catch it (Virex fixed my system after it was infected). What NAV did do was bog down my system performance by 50%, cause extension conflicts and stop me from working while it checked under the bed to make sure there were no monsters (ones it knew how to identify anyway).
The predatory nature of antivirus programs in general really bugs me - they sell it to people by promoting fear (kind of like insurance salesmen, except they have no accountability if their software turns out to be useless when needed - insurance companies pony up). You are much better off taking preventative measures to avoid viruses (if your aunt sends you all kind of stupid email attachments loaded with virii, set your email program to not download attachments, don't install non-commercial software, etc).
As for Norton utilities, they are useless - they do nothing for a corrupted system. Buy a real disk utility (like Diskwarrior) that works when you need it. If you try to recover a disk that won't mount with Norton, you get garbage. Use DiskWarrior and you'll be back up and running in 5 minutes. The only utility I will run from a Norton CD is SpeedDisk - but only for an OS 9 system. Otherwise you're better off with Alsoft's PlusOptimizer.
And while we're talking about Norton, what the hell good is DiskLight? I mean a little icon on the top of your menu bar that blinks when the hard drive is accessed - what possible use could this have?