Port 80 Network Error

I receive the following error when I try to go to various sites:
Network Error
Unable to request URL from host www.xxxxxx.com:80: Operation timed out

I xxx’ed out the real site name as it isn’t important but the problem is.

I have no third party apps running only Norton Antivirus. This just started and I have checked all the Internet Explorer 6.0 settings, have done all the updates and still I get this error on some sites.

AOL lets me get to these sites ok, but I don’t like using AOL for this.

Do I need to delete 6.0 & reinstall it?