If you are using News Show or News Show Pro module from gavick on your site,then you can face a problem of the thumbnails not showing. So,here is the fix.. First of all - image have to be placed in introtext of article. Secondly - support for plugin for Photoslide should be disabled and option "use only plugin images" also should be disabled. And of course image should be enable to show in article in module option (you can find in module options section where you can set elements which will be visible).