Listing employees and their project tasks
Try putting GROUP BY in a sub-select.

SELECT  personTaskProject.TaskCount,
        ppl.Name,
        ppl.Birthdate,
        ppl.Title,
        ppl.Role,
        ppl.Status,
        ppl.Warehouse,
        ppl.StartDate,
        ppl.SalaryBand,
        ppl.Salary,
        personTaskProject.Title
    FROM
        People ppl,
        (SELECT COUNT(t.id) TaskCount, tp.PersonId, p.Title
            FROM TaskPersons tp
                JOIN Tasks t
                    ON t.Id = tp.TaskId
                JOIN Projects p
                    ON p.Id = t.ProjectId
            GROUP BY tp.PersonId, p.Title) AS personTaskProject
    WHERE ppl.Id = personTaskProject.PersonId;


SQL Fiddle