There's a trick to prevent this behavior:


1) Select the pop-up image.
2) Click the "Link" button in the top toolbar.
3) Move the cursor to the very end of the "Script" field. You should see the following code:


... href="#">


4) Change this code so it is as follows:


... href="javascript:void(0);">


5) Click OK then preview the site - it shouldn't jump back to the top of the page when you click the image.