I realize this is a fairly labor-intensive process, but if a couple of folks are willing, please try flushing your DNS to see if that makes a difference. It would help us rule out or focus on possible DNS-related things as we investigate a cause:
- Start by power cycling your router and/or modem by unplugging them, waiting 10 to 20 seconds, then plugging them back in. Once those have reset themselves click on the "Start" button and then click on "All Programs" Choose "Accessories".
- In the menu, find the "Command Prompt" icon, right-click it and choose Run as Administrator (on Win8 hold alt and press "X" and select "Command Prompt (admin)" from the list). If this option is not listed, simply left-click the command prompt icon instead.
- On the Command Prompt window that pops up, type the command below exactly as it appears, hitting the enter key afterward: ipconfig /flushdns
- When that command finishes, there should be a message of "Successfully flushed the DNS resolver cache", at which point please reboot your computer and upon re-entering Windows, and test again to see if the issue persists.
- If after typing in the ipconfig /flushdns command and hitting enter you do not see the success message, or if you received an error, ensure that you typed the command exactly as it appears above.
Thanks!