We're experiencing this on our own site, but I also reproduced it in the Default Example for RadEditor. Steps to take:
- Open the example.
- Go to the HTML tab and delete ALL the content.
- Go to the Preview tab. Preview content is blank, of course.
- Go to the Design tab. Click anywhere in the editor. The cursor will not appear.
- Type any letter and suddenly the cursor appears. Backspace to delete that letter (so the editor content is empty again) and the cursor remains.