Both the best boss and the worst boss I ever had were women, which I offer as my credentials for being fair-minded about this issue (or at least as fair-minded as a man can ever be). The New York Times is really stirring the workplace pot with its article on women bullying women at work.
Observations such as these:
... the male bullies take an egalitarian approach, mowing down men and women pretty much in equal measure. The women appear to prefer their own kind, choosing other women as targets more than 70 percent of the time.
are really tickling the conservatives (such as the blog linked to) and making some feminists apoplectic (a couple of the blogs he links to). I can't personally attest to women "preferring their own kind" when it comes to bullying, but I've talked to enough women who hate the very idea working for other women and cite many examples of the phenomenon. There have always been bullies in the workplace, and too many of them end up in supervisory positions after having bullied out the competition, so I'm not sure why people are so fascinated that women aren't immune from the experience.