Now this has me thinking (dangerous). Could I set the access point to a fixed ip and then configure the TSU9600, which I use solely in the room with that access point, to look for that ip address only?

The way it is now is that I have the TSU9600 to get into the network via the main router's ip. I assume that when the 9600 is close to the AP it will switch to that signal rather than the signal from the main router which is several rooms away. In fact, as has been noted in this forum previously, the prontos do not switch easily from one AP to another. They stubbornly cling to the one to which they initially attached. I found that only if I boot up the TSU9600 in the room right where the AP is, it will pick up the stronger signal from the AP rather than going to the router signal.

So if I can set a separate ip for the AP and then configure the TSU9600 to look for that ip to connect to rather than the main router, do I have to set a different WPA key for that AP even though access to it will give access to the entire pronto subnet?

This might be another subject as I am not certain that this is causing the instability with the RFX9600.