here is my code:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using Infragistics.Win.UltraWinGanttView;
using Infragistics.Win.UltraWinSchedule;

namespace DataBinding_WinGanttView
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            //  Call the method that creates a DataSet
            DataSet ds = this.GetSampleData();

            //  Set the BindingContextControl property to reference this form
            this.ultraCalendarInfo1.DataBindingsForTasks.BindingContextControl = this;
            this.ultraCalendarInfo1.DataBindingsForProjects.BindingContextControl = this;

            //  Set the DataBinding members for Projects
            this.ultraCalendarInfo1.DataBindingsForProjects.SetDataBinding(ds, "Projects");
            this.ultraCalendarInfo1.DataBindingsForProjects.IdMember = "ProjectID";
            this.ultraCalendarInfo1.DataBindingsForProjects.KeyMember = "ProjectKey";
            this.ultraCalendarInfo1.DataBindingsForProjects.NameMember = "ProjectName";
            this.ultraCalendarInfo1.DataBindingsForProjects.StartDateMember = "ProjectStartTime";

            //  Set the DataBinding members for Tasks
            this.ultraCalendarInfo1.DataBindingsForTasks.SetDataBinding(ds, "Tasks");

            // Basic Task properties
            this.ultraCalendarInfo1.DataBindingsForTasks.NameMember = "TaskName";
            this.ultraCalendarInfo1.DataBindingsForTasks.DurationMember = "TaskDuration";
            this.ultraCalendarInfo1.DataBindingsForTasks.StartDateTimeMember = "TaskStartTime";
            this.ultraCalendarInfo1.DataBindingsForTasks.IdMember = "TaskID";
            this.ultraCalendarInfo1.DataBindingsForTasks.ProjectKeyMember = "ProjectKey";
            this.ultraCalendarInfo1.DataBindingsForTasks.ParentTaskIdMember = "ParentTaskID";


            this.ultraCalendarInfo1.DataBindingsForTasks.PercentCompleteMember = "TaskPercentComplete";
            // All other properties
            this.ultraCalendarInfo1.DataBindingsForTasks.AllPropertiesMember = "AllProperties";

            //  Since we are showing a task that belongs to an explicitly defined
            //  project (i.e., not the UnassignedProject), assign that project to
            //  the control's Project property so the control knows to display that project.
            this.ganntView1.CalendarInfo = this.ultraCalendarInfo1;
            this.ganntView1.Project = this.ganntView1.CalendarInfo.Projects[1];

        }

        private DataSet GetSampleData()
        {
            DataSet theDataSet = new DataSet();
            //string projectKey = rm.GetString("projectKey");
            string projectKey = "projectKey";
            DataTable theProjects = theDataSet.Tables.Add("Projects");
            theProjects.Columns.Add("ProjectID");
            theProjects.Columns.Add("ProjectKey");
            theProjects.Columns.Add("ProjectName");
            theProjects.Columns.Add("ProjectStartTime", typeof(DateTime));
            // Assign values for each Project member
            theProjects.Rows.Add(new Object[] { Guid.NewGuid(), projectKey, "QuarterlyProject", DateTime.Today });

            DataTable theTasks = theDataSet.Tables.Add("Tasks");
            theTasks.Columns.Add("TaskID");
            theTasks.Columns.Add("ProjectKey");
            theTasks.Columns.Add("TaskName");
            theTasks.Columns.Add("TaskStartTime", typeof(DateTime));
            theTasks.Columns.Add("TaskDuration", typeof(TimeSpan));
            theTasks.Columns.Add("ParentTaskID");
            theTasks.Columns.Add("TaskPercentComplete");
            //The Task properties are all covered by individual members. But we could save space in the database
            //By storing data as binary using AllProperties and not binding the other fields.
            theTasks.Columns.Add("AllProperties", typeof(Byte[]));


            Guid planningTaskid = Guid.NewGuid();
            // Assign values for each Task member
            // Parent Task1
            theTasks.Rows.Add(new Object[] { planningTaskid, projectKey, "Planning", DateTime.Now, TimeSpan.FromDays(5), null, null });
            // Child Task1 of Parent Task1
            theTasks.Rows.Add(new Object[] { Guid.NewGuid(), projectKey, "Prepare Budget", DateTime.Now, TimeSpan.FromDays(2), planningTaskid, 100 });
            // Child Task2 of Parent Task1
            theTasks.Rows.Add(new Object[] { Guid.NewGuid(), projectKey, "Allocate Teams", DateTime.Now.AddDays(2), TimeSpan.FromDays(3), planningTaskid, null });

            // Parent Task2
            Guid implementationTaskid = Guid.NewGuid();
            theTasks.Rows.Add(new Object[] { implementationTaskid, projectKey, "Implementation", DateTime.Now.AddDays(6), TimeSpan.FromDays(16), null, null });

            // Child Task1 of Parent Task2
            Guid installationTaskid2 = Guid.NewGuid();
            theTasks.Rows.Add(new Object[] { installationTaskid2, projectKey, "Installations", DateTime.Now.AddDays(6), TimeSpan.FromDays(2), implementationTaskid, 60 });
            // Child Task2 of Parent Task2
            theTasks.Rows.Add(new Object[] { Guid.NewGuid(), projectKey, "Execution", DateTime.Now.AddDays(8), TimeSpan.FromDays(13), implementationTaskid, null });

            Guid testingTaskid = Guid.NewGuid();
            // Parent Task3
            theTasks.Rows.Add(new Object[] { testingTaskid, projectKey, "Testing", DateTime.Now.AddDays(23), TimeSpan.FromDays(20), null, null });

            // Child Task1 of Parent Task3
            theTasks.Rows.Add(new Object[] { Guid.NewGuid(), projectKey, "TestPhase1", DateTime.Now.AddDays(23), TimeSpan.FromDays(10), testingTaskid, 20 });
            // Child Task2 of Parent Task3
            theTasks.Rows.Add(new Object[] { Guid.NewGuid(), projectKey, "TestPhase2", DateTime.Now.AddDays(36), TimeSpan.FromDays(9), testingTaskid, null });

            return theDataSet;
        }

    }
}

in the code child task start time should not equal Parent task start time,but result is they are equal...