[support] Drupal 7 Ckeditor problems

[Roger]

I  have a new site with latest Drupal install and latest modules.
3 people have admin access, myself included.
I can use ckeditor 4.3 to edit blocks and pages but the other dev can 
only get plain text html code and no ckeditor. He is using a windows 
machine. I'm using Fedora 19.
We had a supervisor check using an apple macbook and he too could only 
see the code not the ckeditor.

They have cleared browser caches, deleted browser history, restarted 
their machines.
I have checked permissions, roles, modules, rechecked the text 
formatting options and have run out of ideas.

Can someone tell me what's going on and how to fix it please
Cheers
Roger