I've set up the demo version of Supercontainer and it's working on the clients host computer. (It worked fine on my set up as well)

I log in to Filemaker 10 via remote to client's file and don't see the demo or upload file button on the container field. It's there and works fine uploading or copying and pasting on the host computer.

Is this a matter of port forwarding and firewall for the network in System preferences?

What do I need to do? I am not a network person.

The ip address I set in supercontainer container field should be the same as the IP address I use to log in to the fm file remotely, correct?

Thanks in advance.

Yes, you are correct. If SuperContainer is running on the same machine which is hosting your FileMaker database you should use the same IP address as what you use to access the database.

You will need to configure your network and firewall to allow access on port 8020 (assuming you are running SuperContainerServer.jar).

http://portforward.com/ has directions for how to configure port forwarding on many different types of routers.