My problem was similar. It seemed to have happened out of nowhere. I don’t know what I did to cause it but I got frustrated trying to fix it. I was running TinyMCE Advanced plugin and disabled it to no avail. Finally I just decided to abandon TinyMCE altogether and replace it with Dean’s FCKEditor For WordPress plugin instead. It’s a little different but quite nice once you start working with it. Maybe I’ll find a fix for TinyMCE later but for now I have to get BACK TO WORK!
Hope it helps you get back to work too!
