No, they are not synonymous, but they are closely connected, IMO. I feel like a lot of homophobia, maybe not all or most, but a lot, stems from fear of the unknown. I don't mean a fear like a fear of spiders, but something more abstract, and possibly unconscious for some people. So not all homophobes are haters, and not all haters are homophobes.

r-pattz is right. Homophobia isn't a pathological "fear" necessarily, like most phobias. It's a type of fear that inspires hateful acts, attitudes and ideas.

Webster's defines homophobia as "unreasoning fear of or antipathy toward homosexuals and homosexuality." (bolds/italics added for emphasis).

Okay, homophobia is the irrational fear of the same sex couples that there are in the world ( if you have this condition you are afraid of me! ), or as the way i would explain it is the irrational fear of one of your own kind that dares to love in a different way then you *You must be a narccisist XP* and being afraid of men......that is the fear of ANYTHING male XD

The definition of homophobia is "the hatred or fear of homosexuals". If a person fears a homosexual person, it is considered homophobic, but it doesn't qualify as hatred. If a person hates a homosexual person, it is also considered homophobic. It depends on the context of the situation.

The words been thrown around a lot.

"Homophobe" has been used for both the hatred and fear of gays/lesbians, so the definition is becoming somewhat unclear...The original meaning's seemed to be stretched around to fit discriptions.

Just because you're afraid of something, doesn't mean you hate it. Somebody could be afraid of bees because they can sting, but they might still love them because they help in a garden.
IMO, despite the Latin suffix, homophobia isn't necessarily the fear of homosexuals. It can be, it depends on the 'homophobe'. As it's been said, the term's been thrown around.

@r-pattz: Agreed :)

By definition homophobia is a hatred of homosexuals. By definition it has nothing to do with fear at all.