This generally only happens if: 1. You don't close LW down properly before you shutdown your computer. 2. Your comp crashes. 3. You go back to an earlier version of LW.
I'd recommend you make sure LW is properly closed before shutting down LW; give it several mins. Go to Task Manager (control-alt-del) to make sure LW is closing down properly before you shutdown your computer. Oh I just realised, perhaps you have LW set not to shutdown until transfers are complete. Go to LW's menu, Tools>Options>Shutdown & set it for shutdown immediately. Press Apply button.