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/
Later,
Larry