I honestly don't think that should even be an issue. I personally used to RP on a site where everyone was pretty much a girl and they didn't feel comfortable (or whatever) trying to portray a male character so I usually got "typecasted" for that role because I've been a tomboy for along as...
When the other person clearly hasn't read what you posted. My character has introduced himself and two posts later their character is like "What even is your name, you've never said?" If you can't keep any kind of consistency in your replies... I just completely lose interest if the other...