Can you access your main Norton Internet Security?
If you can access Norton, try disabling it first and see if you can visit other sites without having Norton on. If you can, you need to go and change your options or security level. Maybe it's set too high and is blocking everything.
You can also go in and look at the one that it blocked by the log, and enable that site again. But I would only do this if you are sure you know it's safe to give access to whatever is trying to access your computer (most likely a cookie).
Sometimes some Windows updates or other automatic updates interferes with Norton's operations as well. When you're installing new programs or downloading somethings, it's sometimes better to disable virus protection and internet protection before installation.
Hope it works. I can't walk you through it right now cause my Norton is acting up and I've disabled it myself.