I'm sure this has been noticed by others, since I've been seeing it for a very long time now, but the post editor on this site seems to add an extra 2 <br> tags to a post when ever it's edited. So even though I'm typing up my posts with a single space between paragraphs, when it posts, there's 3 or 4 spaces instead. When I click edit, I see <br><br><br><br> at the end of every paragraph. Edit them out, and it puts them right back in.
I just fixed a post (unless I edit it again anyway) and found I had to remove <br>'s altogether. Saving the post made the editor put them back in. Saved again, and it seems to be appearing correctly now.
Anyway, I'm fairly certain that's not expected behavior. Couldn't imagine why it would be. So.. maybe something to fix, eventually? Like I said, it's been that way for a while.