If this was the software forum, I would say that Norton 2005 is trash.
Every time I've worked on a system with Norton 2005 or 2004 for that matter, it has some sort of error and will not work until I reinstall.
When I'm cleaning systems of spyware, I disable startup programs with msconfig and doing that totally trashes norton apparently. Even if I go back and recheck all the startup items, norton never works again unless I reinstall it.