Hi, I've set up an Image library in SharePoint, and have written a tool to upload an Image and a custom thumbnail.
This works like a charm, with the custom thumbnails being shown correctly.
However, users are now uploading videos with custom thumbnails, and though the thumbnails follow the proper convention for naming (are are being put in the _t folder), they are not being displayed on the view form.
If I look at the properties of the thumbnail on the AllItems.aspx page, it's showing the url to be http://foo.com/_layouts/images//icgen.gif, despite the fact there is an appropriatley named thumbnail sitting at http://foo.com/Media/_t/vid_mov.jpg
Does anybody know why sharepoint isn't using the thumbnails I've uploaded for the videos even though they follow the appropriate naming convention and are indeed present in the _t folder?