Check here for info on the various intersex conditions (I just Googled that up to make sure my remark was correct).
As I said I was working from memory from human genetics classes at university.
From your refered site:
Chromosomally Intersexed - probably the most common form of intersexuality involves people who are either missing a sex chromosome or have extra sex chromosomes. The effects of such a condition vary widely. Some people show no outward signs of being intersexed while in others it is apparent at birth.
Genetically Intersexed - technically would encompass "chromosomally intersexed" people too. However it usually refers to individuals who have normal chromosomal makeup (XX or XY) but have a faulty gene on one of those chromosomes resulting in an intersex condition.
Physically Intersexed - the person has physical characteristics of both male and female. Usually this refers to a person with "ambiguous genitalia" (genitals that do not appear to be "normally" male or female). However it is also sometimes used to refer to anyone with a genetic or chromosomal cause, since those are physical characteristics as well, albeit at the molecular level. This term also encompasses those who present with ambiguous genitalia caused by developmental anomolies in the womb of environmental, rather than genetic, cause.
I was obviously refering to genetic defects at birth. There is only one reference to sterility in your source and that refered only to males with one of the the specific disorders, ""70% of Klinefelters males are sterile (though it is believed the 30% who are capable of spermatogenesis may actually be "mosaics" and not Klinefelter males).""
The mosaics have a mix of normal and defective genes throughout their body.