Earlier quoted context omitted.
Usually, yes. But donna is the OP, so I think it's ok for her to acknowledge helpful comments rather than anonymously upmoddng.
And this thread is bringing out a behavior on news.yc that I really don't like -- people downmodding recent comments of the OP because they're mad they can't downmod the post.
And how do you know those downvotes have all to do with the submission and nothing with the comments themselves? Personally I downmodded for lack of relevance.