Yeah, I think I know what you mean. In my line of work, I'm often the only Black person that works at a place at any given time. And in the office we leave the TV on CNN. So sometimes when a black person is being interviewed, and they're being "extra" with it, or speaking ebonics - I find myself secretly cringing. Then I immediately feel guilty for being ashamed of my race.
I constantly have to remind myself that just like I don't speak for all black people, all black people do not speak for ME. We are all individuals, and must stand (or fall) on our own merits - just like any other race.
So in short, don't accept responsibility or culpability for someone else's actions. They don't represent you. Only YOU can do that.