Hello nightwalker and Drift3r,
I don't agree that some people are born homosexual.
The sexual nature of a person is purely physical, if you have a penis, you're a man. Anything else originates in the mind.
Another more important reason why that claim cannot be true:
I believe as a believer in evolution, all animals that were "born homosexual" would have died out. That gene would be long gone by the time ape-like hominids were running about.
And if there is a small number of that genetic homosexuality, it would not be such a large percentage of the population. It would be even less freak of a thing than being born will full body hair, like an ape. Some people are born that way.