In the main content editor, do you mean the page/post content? Like – http://screencast.com/t/UmLif6i2VFSk
The theme doesn’t strip any line breaks or carriage returns out of the main page/post content.
Do you have any plugins installed which might affect the editor, like tinymce etc? If you look in the text view do you see the html for the breaks?
If its another area you’re referring to please send me a link to the live page or a screenshot so I can look in to this further for you.