The 'click on, click off' technique used to select/de-select users under "Select Users" in Task List and Calendar is not intuitive.  It gets cumbersome with large numbers of users - you have to scroll up and down to check whether other contacts are selected.  Please add "Just Me", "Select All" and "Clear All" buttons to that list.  Consider presenting that list in a different manner - maybe check marks like the old group selection in ACT! version 6 and earlier sync setup.