Outlook 2013 multiple windows bug
I run Outlook 2013 with multiple windows open at one time. From the inbox, If you right click on "Calendar" you will see "open in new Window". So the inbox will be in one Window and Calendar in another. If you select an email and click the "Add Todoist" button in the ribbon, you will get the "Add Task" dialog displayed in the Todoist pane of both the Inbox and Calendar window for the selected email. Clicking "Add Task" in one, will close that Dialog. When you switch windows to the calendar, you will still see the dialog displayed.