FSXA Object transparency problem

I created some target objects in Sketchup for a target range scenery. The background is set to 5% opacity in Sketchup. The .dds texture is a DXT3 in the final converted object.

It appears to be generally transparent in that the ground photoscenery is showing thru. However, the autogen vegetation is not (see attach screen cap).

Is this a z-bias issue of some kind? Any suggestions to try with the texture?

Thanks in advance.