>but for 80% of women to have had this problem I'd say there's probably about 80% of the technical community that are causing the problem.
Uh? Pulling numbers out of nowhere isn't helpful.
A small percentage of the population being sexist and the majority of the other being just indifferent (ie this guy made inapropriate comments? Bah, grow a skin) is enough to have a big proportion of women feeling that there's sexism.