Is there anything at all to indicate that it's actually the case that there are 'fewer lesbians than gay men' or is it a question of more men admitting to being gay, similar to more women admitting to being bisexual?
I wish I had more (anecdotal?) evidence to back it up, but for women, sexuality is a really confusing thing - pretty fluid and could go either way until it's settled. For men, it's more clear cut... you know what you are, even at a young age. There's less of a grey area than with women.