Hi Rick,
hmm, do your planes have the same amount of segments? Did you adjust the planes using the front view inside gmax instead of the camera view? Do both planes still are in Y=0?
In general - your overlapping area is too big! You can´t do the softedge blending with more then 25% overlapping.
Let me think about your problem a bit longer, maybe I will get another idea...
Best regards,
Julia