OK got the file :)

I started by importing the boots OBJ file into the scene. I ensured that none of the import option boxes was selected. I then loaded A3 and put her in the zero pose and this is what I got.

The reason that your boots are not fitting A3 when conformed is because the boots do not fit A3 when both the boots geometry and the A3 figure are all at the zero pose. You'll need to remodel or adjust the boots OBJ file such that it does.

I suspect that you modeled the boots to fit A3 as she loads from the Poser library. This is not the same as the zero pose.

Hope that helps.