I understand TB offers the option to create a new tab along the top of the screen, or create a new window for any message, but neither is created automatically when a message is merely selected from the message list. Each message selected from the message list displays in the message pane below, and that has been the way I have used TB for years. However, over the past few months, I have noticed a lengthening row of new tabs across the top of the screen, and not all of the tabs are to messages or folders I have used, referenced or selected in the current or previous TB session. At first, I closed the undesired tabs with their "X", and wondered whether the row had represented only some sloppy mouse clicks on my part. Yet, the tabs kept appearing-- despite my monitoring my own TB sessions, there has been no stray or impatient mouse clicking. The variety of folders and message files represented in the top row of tabs makes little sense-- almost as though an obscure TB setting busily populates the top row with often unrelated new tabs, while I am busy with messages. All the mystery tabs are to valid TB locations, but few are even of interest. One tab refers to a "Junk" folder, and still another to the inbox of an email account I seldom open. Still another tab refers to an account inbox I open daily to check for new messages, but I never have had a tab appear automatically after checking for new messages.