Redfuzzy hit the nail right on the head. I think the real problem, with people, lies in the culture of it all.
I used to date this Mexican girl (I'm Puertorican, Dominican, and Spanish :O). Many of her older family (uncles, grandparents, etc) had a problem with me dating her. And I must say, although we were all under the same boat technically (Hispanic/Latino), the culture was indeed different. And in their eyes, that was a problem.
Now me? I have no problem with it whatsoever. Dating out of your own race/culture is so invigorating because you open your eyes to something new, and you learn about something more than the little bubble you're living in.