Joe,
I think what you are looking for is a port-forwarding setting somewhere in your router configuration. I have a few wireless cameras and I had to specify which port each was going to use to communicate with the outside world. Then, in your router, you need to associate that port with the IP address of the camera.
Its a little stinky to me since sometimes a power drop resets the order of the IP addresses that each camera uses...I'm pretty sure there's a more dynamic way to manage this (I simply put a small battery backup on my wireless router and my cable modem so that power drops no longer affect the configs).
Each router and each camera is probably a little different, so hopefully this general advice can guide you towards making your setup work a little better.
Good luck, cheers, and welcome to the AndroidForums!
