Hmmm...I just signed up for SL the other day and was planning on having a pretty androgynous looking character. Now I'm curious to see how people treat me. I used to play on SL a couple years ago, but had a distinctly feminine looking character with a very feminine name. It'll be interesting to compare the two experiences.
From personal experience, when I had long hair and looked like a girl, people treated me a lot differently than they do now, with short hair and rather ambiguous gender presentation. With long hair and girl(ish) clothes people were perfectly polite at all times, now with more androgynous/guy clothes and shorter hair (I've gotten "sirred" with hair as long as chin-length, and now it's really short, so I get "sirred" alllll the time) people are much cooler and don't exactly go out of their way to be polite, even if they know that physically I'm female. Point being, it really doesn't surprise me that people see androgynous avatars as not trustworthy. It frustrates me a lot, but that's the world we live in, sadly.