I am becoming confused re the Bury Soil model numbers

I am trying to apply soil information to my pipeline model using soil properties obtained from our geotech engineers.

SInce I want to use user defined properties I have set the soil model number to 1 and entered the relevant soil properties.

When I then try to convert the file, I am told that I have to enter other soil properties, ie friction factor, soil density etc. To do this I have to enter the soil models area using the screen icon.

Once in the basic soil models dialogue box I can enter these properties (friction factor etc,) but these values are assigned to soil model number 2. I am only using the user defined soil modeler value 1, so don't understand why I end up having to enter values in the soil modeller 2 to make the model convert since I am not using it.

Thanks