Strange indeed. There still might be a single security setting of your browser that's not what it should be. Firewall to my logic is not the culprit.
There's a trick that might help in the troubleshooting. Google for "anynymous proxies". They are free services that redirect you from their site to the site you actually want to visit. For some services, some popular sites are blocked and not everything is supported, like scripting. See if you can reach your site through any of them.