I find that I tend to read entire paragraphs at once, which is why I suffer from the problem (mentioned above somewhere) that I'm immediately drawn to the one spelling/grammar mistake in the entire paragraph.

Also, if the paragraph is very large (more than about 10 sentences or 60 words), I have to start from the beginning and read it more slowly. As you can image, this makes it very hard to read anything by Umberto Eco or Eric Hobshawm.