Damn lol, I thought you sounded like a young teenage boy when I helped you the other day. I'm useless.....

Oh, dear...
No, I'm a 30-year-old woman. 
...that could be me being on the phone....
A situation that really happened:
phone: *rings*
me: *takes it* A*****. (my lastname)
telephone selling agent: Hello, are you Mrs. A****?
me: No, that's my mother.
telephone selling agent: Oh, you're the son. *changes voice to a tone with which you talk to little kids* Is your mommy home?
me: .....No. 
<--- 29 year old woman 
Back on Topic: I never noticed any sexism in DAIMP, but that could be because my headset (mostly my mic) doesn't work most of the time. 
The only funny thing I once noticed was a German guy, who talked in German with his friend and whenever he talked to me, he would talk in englisch.
(it was late in the night and I think he thought I might be from the USA or so
)