Not sure if this helps, but I get the same issue when trying to access my test setup through the company firewall, I can get in by clicking a link in my email when I have signed into iNotes, but once I get to the site, I can only see content that was made public, items in the "internal site" just show the reloading indicator as pictured in Patrick's initial note. BTW, the firewall messes up a number of other Notes items that I am not sure how to address.
Also, I am trying to find the reference material that speaks about firewalls, but could not locate it.