@jeepr:
Yes, MyHouse is still a bit of a troublemaker. It's because of the way it was designed to work in browser as an ActiveX control.
The Mobile Apps use an entirely different interface: They're actually web pages served by your computer to the internet.
With the regular Mobile Apps, they're served internally to your home network (WiFi or Wired), and work that way. With the "Pro" versions, you can use a direct link to your internal network, or decide to use the X10 Reflector to view the page - either method has worked for many, if not all of us here with the Mobile Apps.
To access any of the regular Mobile Apps outside of your home network, you can use Port Forwarding on your router (as you had mentioned). When you buy one of the Pro apps and get the Reflector service, you don't have to worry about Port Forwarding, and it automatically extends that ability to all of the regular Mobile Apps.
As a side note, of course, I don't work for X10, but I do use it without any hitches. I even set up ActivePhone with public access the other day and let people control my Holiday Lights from the web. Worked without a single problem! I also use it on my old P4 2.2Ghz (non Hyper Threading) with 1GB of RAM, and I can still use that same computer for Bill's Voice Commander, serving media to my Xbox/PS3, and more.