To record additional, manual notes against driver records you need to go to
View Data Drivers -> Calendar View screen.
Select the relevant driver and to view their monthly calendar and then locate the required day. Double left click on the day to display the driver's activities.
Located near the bottom of the screen is an area to add Driver Notes and Driver Errors. Ensure that you click on the 'Save' button once you have added all Notes/Errors for the given day.