I have created a simple page to display a few photos I have but 3 of the 9 thumbnails do not display the correct full size image, the default photo is displayed instead.

I have downloaded the latest version of WD6 and am using Template 5 from the Photographer Theme Designs Gallery. My first attempt had 5 incorrect full size images; thinking I had done something wrong when editing the rest of the page I made a second attempt from scratch and was careful to ensure that the template photo was selected in fill mode before dragging the photo from an Explorer window. The thumbnail changes instantly to that of the imported photo but when I export the site, the default photo appears in the big window when you mouseover. Needless to say the picture in the _htm_files directory created during the export is the wrong big photo (thumbnail okay).

What am I doing wrong?