Question about the DateTimePicker object

[Beagley]

I'm writing some software that keeps track of issue dates and expiration dates. When a user adds a new record to my database I have code that defaults them to these values. Here is the code that does this......

Issue_DateDateTimePicker.Value() = Date.Now()
 
If IsDate(DateAdd(DateInterval.Year, 1, Date.Now)) Then
            Expiration_DateDateTimePicker.Value = DateAdd(DateInterval.Year, 1, Date.Now)
Else
            Expiration_DateDateTimePicker.Value = DateAdd(DateInterval.Year, 1, Date.Now)
            While IsDate(DateAdd(DateInterval.Year, 1, Date.Now)) = False
                Expiration_DateDateTimePicker.Value = DateAdd(DateInterval.Day, -1, Expiration_DateDateTimePicker.Value())
            End While
End If

When I save the record I get an error message that the Issue Date field cannot be null. I have this validation rule set up in the database, but I'm confused as to why this error even occurs. I can pull up message boxes that show the values of both of these objects and they are definitely not null. Any help??