ix3D Ultimate Rez cards and two monitors: it won't work?

Thomas Ainscough writes: "I just ordered two ix3D Ultimate Rez cards for my G3. After installing them, I found that selecting any resolution or color setting in either the Monitors & Sound control panel or the ix3D control panel causes a system freeze as soon as the mouse is clicked. ixMicro tech support confirmed this, adding that "current ix3D Ultimate Rez drivers don't support two video cards in all machines." They told him to return the cards if he wanted to use two monitors.

However, a MacWEEK article reports that "ixMicro is preparing to maximize the slot allotment in Apple's blue-and-white Power Mac G3s with a new graphics card that will drive two monitors simultaneously."

Update: Rob Morton has two cards and two monitors running off of his Power Tower Pro with no problem. Maybe this is what ixMicro meant by saying the cards do not support "all machines;" that is, they do support some machines.