I lost a game to a girl once, that I know of, but probably beat by many more I was unaware of. It doesn't bother me, but being beat by 12 year olds does when they're not taking the game seriously enough.
That rarely happens though. I just don't lose
She was the worst player on her team. Halo 3, bunch of American 50's and her at rank 20-odd, in team objective vs my friends and I at rank 25-odd. That's Trueskill ranking system for you though.
They beat us by a fair bit, and the cross-atlantic American connection didn't help. They were all being arseholes too yelling "Haha you got beat by a girl!" "You all fucking suck." "Go play a different game - give up Halo!" and she was laughing and trashing along with it. The fact we lost didn't both me, but the fact these people were rolling in their victory over a disadvantaged and severely less-good team pissed me off, and she was a contributing member of it.
I was pissed off at them all equally. It was one of the most scumbag teams I've ever fought against in an online game, but I remember it clearly because they were trash talking as though being beat by a girl is something to be ashamed of, and she was loving it too.
But for the most part I don't care who I beat/who beats me online. Your gender and race and nationality isn't something to form opinions over, it's how you play and communicate that matters...
[small]Though there are trends between certain nationalities and play styles. Italians are generally the dirtiest players online, for instance, doing borderline-impressive but dirty-as-hell techniques to win, and Germans are inhuman at twitch-shooters.[/small]