mich@el

FWIW, I have installed the CKEditor and that seems to be working

Thanks, have gone through every file in /wp-admin and /wp-includes and every single file is 755 or 644.

Sorry, not that either. I checked :

/wp-admin/images/
/wp-admin/js/
/wp-includes/js/tinymce/themes/advanced/img/
/wp-includes/js/tinymce/themes/advanced

and all files in those directories are already 644

I’ve got the same thing – just upgraded two sites from 3.1.4 to 3.2 (both hosted in the same cpanel).

One site upgraded OK (addon domain in a directory), the other (main site for the cpanel) the post editor no longer works.
– All plugins have been disabled / removed
– 2010 & 2011 themes both have the same issue.

I’ve tried in both Safari & Chrome, both have same issue.

public_html/wp-includes/js/tinymce has 755 permissions.