Thank you for your post, and I apologize for the late reply.
If you are trying to open the database via FileMaker Go, then you don't want Instant Web Publishing. Make sure you have FileMaker Network sharing turned on and allow access. Also, make sure port 5003 is open. This is what FileMaker Pro uses to share database files.
In FileMaker Go, add the host address 207.229.xxx.xx. Do not add port 80, as this is used for Internet interaction.
Make sure there is no firewall set up, or a router allowing only specific IP ports. For example, I can connect to a database file internally via company Wi-Fi, but when I try 3g, I am blocked by the company firewall. Therefore, go to another computer (laptop or desktop) outside of the local area network, launch FileMaker Pro, and view files for host address 207.229.xxx.xx. If this works, then FileMaker Go should work. If not, check the local area network router settings for allowing (or disallowing) external access.
If you have already found a solution, please post it so others can also benefit.