The commenter you are replying to is a guy, so him saying he charms his clients is not relevant to your issue. I worked in a professional services field, although I doubt it's what you do, based on how you describe your situation. To the extent that I could, I worked like a man (read further before making an assumption about that), and I was very successful. First, men don't work the same way as women do, and there's often a boy's club mentality, with favors, "meetings before the meetings", etc., being prevalent and significant to the success of many male professionals. The reality is some male professionals will not be nearly as good as you, but they know how to play by the rules. If you don't know how they work, and at least compete with that, it's difficult to be successful, unless your skills are in a league of their own with no other competition. It doesn't sound like you're there, based on your comments.

You might want to enlist a trusted friend to give you feedback on how you present yourself at these conferences and to potential business contacts. It might be that you are dressed in a way that seems unprofessional to men, and it's more difficult for them to take you seriously. Unless you are in a profession that expects it, don't use your sexuality, as most professional men, especially older professional men, will dismiss you as a serious business person, and see you as someone whose only skills is using your feminine wiles to get ahead.

Also, learn about how women interact and communicate differently than men (for example, nodding our heads as we listen; men don't do that), and try to interact and communicate more like them, so they aren't mistaking your intentions. While you don't need to be a bitch, you need to present yourself confidently, with no fear of intimidation by others, especially older male professionals. You have to learn to be psychological and use that to your advantage, as well. For example, when negotiating, don't be quick to fill in the silence; instead, use the awkwardness to your advantage. When you can tell a man is a blowhard, let him talk all he wants, while you listen and take mental notes about what he says, as he will almost undoubtedly give away information that will be useful to you.

I found that being a bit underestimated by men was a good thing, as their guards were down, and their egos weren't constantly on their minds. I also found that not being too sensitive to the male bullshit is a good thing, but you have to be careful not to let it swing too far, as being too open and accepting can be perceived as being sexually open and accepting. If you can remain unfazed and even better, can banter with them, it's a huge plus for you professionally.

As far as how to learn about some of these things: I was actually taught the skills by my employer, and my partner mentor. There are likely videos floating around online, and/or books available on the topics, to help you. Like so many things, you can learn the theories and principles, but you have to use it in practice to get good at it.

Good luck!