We moved the site to new servers in July. Since then we have had several folks who have had access issues such as what you describe.
The problem comes from an interenal conflict in your computer. Your computer remembers us at our old address while your browser is trying to connect to us at our new address. The conflict causes a hangup which looks like a connection problem.
I'd really suggest doing two things: Clear your browser cache (see http://www.wikihow.com/Clear-Your-Browser's-Cache} and then try flushing your DNS (see http://www.whatsmydns.net/flush-dns.html
There are a wide variety of issues at play here, most of which we cannot control from here. You could also be experiencing a blockage caused by your anti-virus software or, and this is very suspicious because you are experiencing issues on multiple locations from one general area, it could be a problem caused by your local ISP.