What I found was that the installer was still trying to connect to the activation page even after closing the application. I found this by trying to move the install file. It told me that it was still trying to access the site even though it was not open or running in my system tray.
I closed out of everything and restarted my PC. On reboot I immediately moved the install file to my desktop and ran it again, this time selecting that I had already activated D3. The installer started installing immediately and is progressing at about 1 percent every few seconds. As I type this I have gone from 10% to 27%.
Hope this helps some of you out there.