I am out at work, but not presenting there. Being called sir drives me nuts, and co-workers would some times say it humorously or as a habit. I told them it bugs me, but I addressed it with humor, whining or sarcastically glaring whenever they did it. They all stopped using it and most of them will say stuff like miss, senorita, lady, chick, etc. instead. It probably helps that I'm very effeminate looking thanks to HRT and hair down to just below my ribs.
I've found that if you chastise people for saying stuff like that to you, it will probably stress them out. Turning it into an amusement or a game encourages them to accommodate you. Many of the people at my work are quite a bit older (50+) with a few people around my age, in their 20s. None of them were terribly well educated on the subject and several are republicans and Christians.
Being really kind, friendly and humorous goes a very long way. Not to say that you haven't been, of course; I couldn't know. If you haven't tried this route, though, it may be worth looking into.