First, a comment: I'm not sure what you intend here, so I may be wrong, but I think you're doing things the hard way, using standard environments for things (titles, headings) when specialized environments for them exist.
That said, the reason for the difference in spacing is that in the first block of text you entered each line in a separate paragraph, while in the second block you entered it all as one paragraph. If you redo the first block in a single paragraph, you will eliminate the extra spacing. Should you need line breaks in places they do not naturally occur, use Ctrl-Enter rather than Enter. Paul
