My issue was resolved with the new router I bought. I don't think you need to go all out like I did (though I'm pretty happy with what I got). I think any netgear will do. When I hooked the new router up, I re-arranged things again, and put the XHS router beheind it. After it was all set up and working, I went up stairs to check the control pad and everything was working without any additional settings on the Netgear. I didn't even have to do a reset on it; but, I did anyway just to be safe. Everything is working great now. I'm getting text messages again, the internet aps are working, and the timed arms and disarms are working. I don't have any camaeras hooked up, so I don't need to mess with that.
In fact, I'm so happy with this setup that I think I'm going to cancel the gateway that is supposed to be installed on Monday. I am getting my speed and then some with the new setup. If I get a new gateway, I'm going to have to bridge it anyway to prevent double nat and such and that would illimate all the added features anyway.
I don't know why the Linksys would not play nicely with the XHS router behind it. It was the EA6900, and not even a year old. Has anyone gotten an XHS router to work behind a linksys router?