I wonder if you are having a "loop back" issue: Take a look at the accepted answer on this post: Installation issue with SDL Tridion 2013 & SDL Web 8 CME not loading all items properlyInstallation issue with SDL Tridion 2013 & SDL Web 8 CME not loading all items properly.
On my servers I typically disable this if I need to access them from the local server: http://www.information-worker.nl/2009/06/23/disableloopbackcheck-on-windows-server-2008/