The One with the Formatting

Why, why, why do my spaces between paragraphs not show up? Blogger seems so fickle. Sometimes my posts show up the way I format them; sometimes they don't. Look at my next post. Some of my paragraphs have double spaces, some don't. I continuously go back and forth between 'Preview' and 'Hide Preview' trying to fix it when this happens. Then I publish my post, then I go back and edit it to try to fix it, publish it again, back and forth, back and forth. I am way to anal about this kind of thing to just shrug it off. If someone can tell me how to make Blogger do what I want it to do, I will give you $5.