Adding parent parameter causes entity to disappear

when adding the parent optional parameter to any entity at creation OR when using EntityParent I lose the child entity.

For example
dim sun as integer = CreateSphere(64)
ScaleEntity(sun,10,10,10)
PositionEntity(sun, 0,0,10)
dim earth as integer = CreateSphere(64,sun)
PositionEntity(earth, 0,0,100)

If I run this the erath sphere does not show on the screen.
However, if I remove the parent parameter and run it the earth sphere appears normally.

Any ideas an what I may be doing wrong?