I’m 38, and have never been comfortable with the Gen X thing, though I guess I fit in some ways. I’ve always considered people born between about 1960 and 1972 to be some of a “middle generation.” I call it the Westerberg generation. Google it if you don’t get my tagline.
If you go back to the original popularization of "Generation X", (from the Douglas Coupland book of the same name), it referred to a very narrow group, born between 1960 and 1965, who really are in the demographic shadow of the boomers. It was such a catchy term, though, that it was used to describe a much larger, and later, group.