Did you perform all steps from this guide: http://www.hotspotsystem.com/installation-guide-openwrt
Please note that we have an OpenWRT build specifically for that router: http://www.hotspotsystem.com/firmware/openwrt/UBNT/airrouter/
It is much easier to configure the router using our build. Reset the router’s settings and use the following setup guide to configure the router: http://www.hotspotsystem.com/openwrt-hotspot-setup