So the house dimmer is tied into the same line as the rest of the lights, and you have both the x-fade and compu controlling them with an a/b switch?
You are saying all the lights work ok when controlling with compu, but when you switch it to the x-fade the leds go nuts? If so, they are probably losing dmx since the x-fade is only 6 channels. The only option you have is to set the leds so that when they lose dmx they do not go to auto mode.
Finally, you can also add a wall panel from the compu box with 8 scenes using easy stand alone. When you start the software, the box will be inactive. This isnt talked about and alot of people dont know it, but if you want to know how to do it, let me know.