hi aik, at my work, i use hfs 2.1beta 14 and i have too more than 3 network interfaces, one from hamachi, one from local area network another one wireless, and another bluetooth, and using the right ip of each interface i can access it in all of then, i just have to write
http://IP-FROM-ANY-INTERFACE-OF-MY-SERVER:PORT-CHOOSEDand it works, it works on pocketpcs that access the hfs via wireless, it works on some gsm phones via bluetooth, it works on my lan (off course it works) and througt my wan or over internet.....
and about the checkbox that you are refering i guess that you don“t find this but ther is a option to accept connections on any adress