CLAMP will soon be releasing Moodle 1.9.9+LAE v1.1.3, which fixes an issue with TinyMCE not displaying in text fields. We hope to have this release out by the 1/28/2011.
The fix for this problem is straight forward and involves updating a few lines of /lib/editor/tinymce.js.php; details can be found in this Redmine Development thread.
Update: We’ve released Moodle 1.9.9+LAE v1.1.4, which fixes this problem. We skipped over 1.1.3 for strictly logistical reasons.