Changing the preferences should stick, but your browser may be caching the stylesheets. Do a forced refresh or reload. If you're still having problems, let me know and I can make sure it's taken in the Database.
I don't know if there are editor specific help. Not quite sure about why the smiley's aren't working either. I'll let you know what I find out.
I know it's not a great solution, but m00kie found a Firefox extension, I think it's called IE Tab or something like that. I think he said everything seems to work fine using that.
I use IE most of the time, and everything works fine there. I'm new to firefox so I have to find all the quirks first before I can fix them.