Schedule Wizard stores your task information in an efficient and compact manner. Tasks are placed in the database once with a flag that indicates if it will repeat or not, in a manner similar to a VCR or alarm clock.
One of the most common reasons for a task not being shown is that your "List of Scheduled Tasks" window is showing a single-day view, and the task in question is not due until after the day shown. To view all tasks, simply click on the "All By Date" tab. You can make this the default view whenever you start Schedule Wizard by selecting File->Setup, then the General Tab, then ensure the "Show full schedule initially" checkbox is checked.
Note that you may also opt to show only active tasks.