After trying to do a fresh install of Zentyal 3.4 a few times unsuccessfully I just gave up. I tried multiple discs and USB flash drives to no avail. Come to find out recently thats a bug in the Ubuntu 13.10 installer. It disables some motherboards USB ports during installation. Right after language selection the system appears to hang. The keyboard stops functioning, caps lock nor num lock respond.
There is a work around! If you can, use a PS/2 keyboard and problem solved. If you can’t some people mention unplugging and moving the keyboard to a different USB port works for them. There are also reports of using a USB switch to bypass this issue.
During all of my searches I found this page to be of the most help:
http://askubuntu.com/questions/377728/usb-keyboard-stops-working-on-installation-at-language-selection
Hopefully this saves you some time.