Preconditions: content type with richtext created.
Steps:
1. Click on Create button
2. Choose the content type with richtext
3. Put some text in richtext field, for ex. two paragraphs
4. Between two paragraphs embed an image and use "align left" button
5. Between these two paragraphs (again) embed an article and use "align right" button
6. Under the second paragraph embed another image, place it in the center.
7. Move the image from step 6. up using arrow button. It's located right now in the same line with the first embedded image and article. They are both "disabled" by the image in the center - you can click on them but nothing happens.