Why in the “autothumbnails” mode the thumbnails are created not for all pages?
When creating autothumbnails the page has to be downloaded as a whole first. If the download takes too long (the pre-set value is more than 5 sec) the operation is aborted and the next page in the autothumbnails queue is processed. An alternative way to create a thumbnail image is to use the “Thumbnail” command in the Browser View. Also, a thumbnail image is always created for each page which has been opened in the viewer.