Transphobia very typically includes projecting a heterosexual orientation onto transswomen*, and if frequently associates gay men and transwomen together. In it's most insulting form, it comes out suggesting that we are gay men who can't handle the social stigmas of being gay, or even that we just can't handle to pressures of being a man. Transphobia not only targets transsexuals, it frequently targets other groups, especially homosexuals. But what is the worst, and even more saddening, is when the homosexual community and transgender community turn on each other, even to the point of transsexual denouncing homosexuals (and probably bisexuals, but it's never brought up).
And of course there is also transphobia within the transcommunity itself. In a discussion at a transgender forum, I have been accused of not "being real" just because of my preference of wearing jeans. Even though I've always delighted in the fact I can find women's jeans in my size much easier than I can in men's since I've started wearing them, and because of this ease I also have an actual variety to choose from, rather than just having only one or two different styles to pick from, which thrills me, I get told I'm "not real." Even being unable to tolerate what society has largely labeled "chick" music and being infinitely annoyed with emotionally gaggy and patriarchal conforming "chick" flicks is enough to make some in the transcommunity question your identity. IMO, this is the worst kind of transphobia because we are doing it to each other.
*this, at one time, was actually a requirement for transitioning. If you weren't attracted to men, you failed to meet the criteria. Fortunately, much progress has been made in that regard, as transwomen now do not have to be attracted to men, or even have to take jobs that are more traditionally "female." But it does show their are very strong patriarchal and monosexual roots even in psychiatry and psychology.