Having same problem...
I am having the same problem. If my results page is in the root folder, i.e. page.php, my path to my image may be images/001.jpg. But the page with the editor is in a sub folder containing all of my password protected CMS pages, cms/pages/insert.php. So, when I create the page, it shows up fine on the results page, page.php, but in the editor, two folders down, the image links are off. This was not happening in HTML Editor 2. At this point, I am going back to version 2 as clients are complaining that they can't see the images in the editor.