Your Lightsphere® is not defective.
abnormalities are commonly referred to as lens flare. The reason for
lens flare is that errant light is bouncing around inside the elements
of your lens. This can be from direct bounce or from an angle. We
strongly suggest using a lens hood/shade when photographing and always
been mindful of shiny surfaces or reflective materials.
For further insight on lens flare and the optics lenses, we suggest this Wikipedia article: http://en.wikipedia.org/wiki/Lens_flare