I tried the earlier version of firmware (I have the latest, as it turned out) for the miniPCI card, and I could successfully change the MAC, but I couldn't connect to my network, even with the original MAC.
I cannot find any, much less newer firmware for the AP. It is an Xterasys WAP257. My setup has the DSL router sending to this Xteresys POE AP to then connect to a directional antenna which transmits to another house on my property. POE is essential since the AP is a good distance from an outlet, and I want to minimize signal loss with a short cable from the AP to the antenna.
I would like to add another AP to rebroadcast the signal in the other house, since it has a metal roof which degrades the signal quite a bit. Currently, I get good signal at the windows facing the sending antenna.