Norton will get to the point that inconsistent operations of the game and many other programs will start happening. Especially anything that does a number of updates to its own config files.
Typically, you have to remove Norton, then re-install it to get things back to some level of sanity.
I have seen Norton cause some really bizarre problems. You cannot disable it, for one thing. Disabling it just causes it to not report what it thinks are problems. It still mucks with all your files. Horrible program.
