That's an interesting problem...
BUT the issue is most likely with the editor, and the fact you may be using » View » Edit Using Theme
If you're having issues with your theme, or need to troubleshoot, turn off the theme and try editing without it.
In Windows Live Writer » view » edit using theme [or CTRL-F11]
AND/OR
Windows Live Writer doesn't always detect the themes correctly, and its terribly irritating to come across this issue.
But you SHOULD still be able to use Windows Live Writer with those themes; you just need to make some manual adjustments. I've an article that are some options for Windows Live Writer users to try to help them with their theme issues.
http://www.lehsys.com/2010/02/windows-live-writer-creating-a-custom-template/
I hope this helps...
Until next time,
LEHenryJr
LEHSYS.com
If you this answers your question, please 'propose as answer' for other users.