A management position opened up in a company I used to work for. Several of us applied, most very competent. We all went through the first round of interviews. The person doing the hiring specifically told me (before I applied) what the qualifications were. After the the first round, I was informed by said manager that though I was in the top 2, I would not be moving around to the second round. Why? Because there was a female candidate. They changed the job description and people who wouldn't have been qualified by the original description made it to the second round. Guess who got hired? I found after that she had help from HR writing her resume and was coached on how to interview for the position as well. This wasn't hearsay either. She actually told that to a friend of mine. She had also pretty much demanded to be put in a management position even though she had a track record of not doing work - pushing it off on other people with less experience and not mentoring them properly.
A year or so later, I needed to talk to her right after a meeting finished. I wanted her to reinforce a couple things with one of her engineers - not in a bad way, just to make sure we were delivering a coherent message. She kept trying to blow me off so I eventually lost my patience and dared to raise my voice a bit. She wound up delivering the EXACT OPPOSITE message to the engineer which sent him through the roof, so I had to go and smooth things over with him. But guess who had to apologize? What p*ssed me off further was that my boss kept making excuses for her when he ordered me to make the apology.
So yeah, there's gender bias at work.