Check AdminCP > Settings > Options > Style & Language Options and make sure that Default Style for Modern Mobile Browsers and Default Style for Old Mobile Browsers are set to NONE, not to your default style.
That was the first thing I did, when I read several other threads about this topic. It has not worked for me.
--------------- Added [DATE]1330883765[/DATE] at [TIME]1330883765[/TIME] ---------------
I'm not great at tracking down stylevars and templates, so would someone be able to tell me where the files are stored for the editors, and which template actually creates the posting form, including the insertion of the editor?