For your "Site Options", what option do you have set for "Content Editor". I remember having the same problem that you just explained, some some site that was using the the software as this site, but I was using IE7 then.
It almost seems to be a browser compatibility issue with "<div> </div>", which is what is being used for new lines. I think that should be replaced with a simple "<br />".
Edit:
Actually, upon posting "<div> </div>" is replaced with "<div></div>".
Susan, I looked at the source of this page. Did you write your post with an HTML editor? You post doesn't use a single div tag, it uses paragragh tags "<p>", wich would explain why you get double lines, instead of a single line.
"God did not create evil. Evil is a result
of what happens when man does not have
God's love present in his heart. It's like the
cold that comes when there is no heat, or the
darkness that comes when there is no light."
Albert Einstein