ActiveX checkbox wierdness

[Dave C]

Director 8.5, with a Microsoft Forms 2.0 CheckBox and a simple behavior

property spriteNum

on change
  put spriteNum
end


Clicking the checkbox gives
-- <Void>

Easy to get around by hard coding the sprite number ( i.e. 
sprite(14).value instead of sprite(spriteNum).value ), I just  find it 
odd. Does this happen in later versions of Director as well?