Just FYI, any Norton product for Macs are highly NOT recommended. Some examples of why this is:

This has been made mentioned in Wikipedia as well.

The problem lies in that Norton products slow down the machines and causes a lot of problems even after uninstallation.

If you really want AV software on your Mac for non-existent Mac viruses, or you want to prevent viruses being spread to Windows PCs you can use these ones:

http://www.clamxav.com/

or

http://www.intego.com/isb/