The Gay Gene

This might not be directly on the topic of the big questions but I read about it and it started my mind thinking so......
After Dean Hamer published his article on the gene that seems to be responsible for homosexuality, there was a flurry of media coverage on the subject. It seems to me that it is an evolutionary improbability. Individuals who have the gene should be selected out since they have a lesser tendency to mate with the other gender and produce offspring that would propagate the gene. I cannot think of a reason why the gene would evolve in the first place. What advantage would there be in a gene that would decrease the chances of producing offspring?