I just tried custom edit mode to scatter geometry to follow along the path.
created 2 spheres, converted then to edit poly, resetted their pivots so that they are at the bottom of the geometry and then resetted thier xform and converted then again to edit poly.
Created a line and scattered the 2 spheres using FPP along the line using custom edit mode, but as soon as i did that the spheres got scaled along the z-axis.
I think either i am doing something wrong or there is some setting that i missed.
please help because after getting this file right i am going to apply the same technique to one of my projects.
Note : sphere are just for reference i will be using archmodel trees for scattering along the path
Attached is the image and the max file for reference...(.max file is 3dsmax 2015 version and vray 3.60.03 and FPP 5.4.1)