When I create a new post, quicktags appear properly in the post editor.
When I open a draft, quicktags fail to load. The HTML version of the draft post appears in the edit box but then things stop loading. The quicktag buttons never appear.
'Use visual rich-text editor' is switched on in User Options for the user acct attempting to edit a post.
I have re-uploaded the WP-INCLUDES directory from the unpacked install files stored on my local drive.