With the latest build (2005-10-12) I noticed a problem with the tinyMCE editor when you write post in the global site admin.
When you try to load the "insert image" popup or the "html source" popup I got this javascript error in console:
Error: tinyMCEPopup is not defined
Source File: http://mydomain.com/wp-includes/js/tinymce/themes/advanced/jscripts/source_editor.js
Line: 16
And nothing appears.
This doesn't occour if I write post in a "user blog".
Any hints please?