Drag the link below into your link toolbar! (NOTE: This is a fix for Firefox only). This button will help you retain linebreaks entered into your blog entry without having to hand author the necessary HTML.
When you are editing an MSN Spaces a blog entry (using FireFox), click on this toolbar button to quickly convert line breaks to the HTML <BR> element. The <BR> will cause your text entries to break correctly. You can create double, triple, etc., spaced text by clicking on the button multiple times.
For more information, see my blog.