Description of problem: Downloaded Publican-Installer-2.3.exe from https://fedorahosted.org/releases/p/u/publican/, but at the end it tries to download things like docbook and it is not able to open a connection. A proxy is configured in Windows and both IE and Chrome are using it without problems.
The download capability comes from NSISdl, as documented [1] this should support proxies. Might be a Windows version or old NSIS used in 2.3. Will need a Windows user with a proxy to test. 1: http://nsis.sourceforge.net/Docs/NSISdl/ReadMe.txt
No way of duplicating this even if the windows build wasn't broken.