Again, this is not just a North American problem. My maiden name is Clark, and I can think of a whole culture that can't pronounce it. It doesn't get much simpler than "Clark," but I'm not going to look down on my Chinese friends because an L and an R back to back is something they don't run into very often. My Russian teacher can't say the word "vowel" to save her life, but it's not because she's uncultured.