You should have used a reserved TLD like `.local'. If you set it as the local domain name `ai' and `ai.local' would work. `ai.' would not work, as the dot at the end tells it to look at the top level. (like the slash at the beginning of an absolute path)
I called my FreeNAS box freenas because I didn't feel very creative, and I can browse to it as http://freenas or http://freenas./ but if they took a domain of 'freenas' suddenly that means I have to do extra work and rename my stuff. Doesn't seem fair!