Guest account can't access internet: what gives?

I just got a new laptop with Vista on it and I turned on the guest account in case a family member wanted to use it. When I logged on under the guest account, it wouldn’t load any pages in IE or Firefox, even though it was connected to the internet. Then I switched over to my account to see if I was having the same problems there but it let me through just fine. When I switched back, suddenly I could access the internet. Now this morning I tried to see if it was still working in guest mode and of course it wasn’t. Any idea what the problem could be? I already set up Norton to allow IE and Firefox through. I tried googling but couldn’t find anything relevant.