Oh well, can't find it...I guess I'll try and type it out again.
Why women are not funny, according to Nef:
1) Being funny is a learned activity, as well as a talent. But that talent has to be nurtured early on in life. learning what is funny and what isn't means throwing out some duds and risking your joke falling completely flat. Men are known to be bigger risk takers, and humor is a much more integral part of how men bond with other men than it is in that of relationships between women. So they not only have more incentive to take the risks to "learn" what gets people to laugh, but they ahve less fear of the risk.
2) ATW already hit on this point, but it's true. if you accept that one learns to be funny through feedback, you're going to have a lot of women who have guys laughing to humor them or to try and get them into bed, thus they think they are getting genuine positive feedback, but they are not. So even when the dud is getting thrown out there, she's not learning that THAT particular thing was not funny - reinforcing her lame sense of humor.
3) Finally, the worst thing, in my opinion, is women who try to be funny in the same way that men are funny. Hearing a women make jokes about smelly balls is just not really going to be funny. The kind of humor I laugh at the most is the kind I can relate to in some way. I can't relate to Sarah Silverman making jokes about smelly balls. Neither can a guy, because it's coming from the mouth of a pretty female. There's something inherently incongruent about it.
That said...I have laughed at both Stilleto and Smurfy. I think some women are funny...it's just not biologically necessary for us to develop that skill, so less do it.