OK this book sounds ridiculous and I can't be arsed to click on the link either!
BUT...(and before I continue let me say that my DSis is gay, I have gay friends and am likely to ask two of them to be godparents)...BUT I did used to know a guy who was genuinely unhappy about being gay.
He was a Christian and genuinely felt it was sinful etc. His own theory was that he had had a very difficult relationship with his father, plus he wasn't your stereotypical sport-loving boy either. His own father used to call him a 'fag' (he's American) etc. He thinks he kind of fell in to being gay as a way of getting positive male attention.
Of course I don't know if any of this is correct - but this is what my friend genuinely believed and more to the point, his orientation was making him very unhappy. He did go on one of these courses and in is own words, it worked for him. He got married (to a woman!) and had two girls.
Now I just have his side of the story but wanted to share as I find it very interesting.
I think my view is that absolutely no-one should be made to feel like they're 'sick' for being gay but I have seen the other side - that some gay people don't want those feelings.
Whether that's their genuine view on their sexuality or whether that's societal or religious pressure, who knows.