Well, the statistics are inherently skewed toward the "no difference between male and female roleplaying behavior" because we are talking about women who roleplay. Of course they're going to be prone to powergaming and combat and such. That's a big part of what roleplaying is. It doesn't mean that if the "average" women was forced to roleplay for whatever reasons that they would be equally as likely to powergame, but the difference between an average male roleplayer and female roleplayer is theoretically much less than the difference between the average male roleplayer and female non-roleplayer.
A female roleplayer is much more prone to read comics, watch [shonen] anime, and other male dominated hobbies. Back in college, over half the females in my anime club played PnP RPGs (Ars Magica, Vampire, D&D, etc) and more played video games. I'm sure if you went down the hall to the Sigma Gamma Rho Sorority, then they would not exhibit the same behavior.
So I think the answers presented here are perfectly accurate, not being skewed with anecdotal data that is fed by bias. Because the subject of the poll is already skewed to that effect. In a way we're comparing slightly off average males to highly off average females.