استشاره : ما الخطا فى مشروعى هذا

ما الخطا فى هذا الكود

حيث ان البرنامج يسجل حقول وليس هناك اى مشاكل ولكن عند الحذف يحذف تمام ولكن عند الضغط على button3,button4 يعرض رسالة خطأ

DataBinding cannot find a row in the list that is suitable for all bindings

وهذا هو البرنامج

Imports System.Data
Imports System.Data.OleDb
Public Class Form1
    Dim ConStr As String = "Provider=Microsoft.Jet.OLEDB.4.0;" & _
"Data Source =" & Application.StartupPath & "\MyData.mdb"
    Dim Conn As New OleDbConnection(ConStr)
    Dim DataSet1 As New DataSet
    Dim SQLstr As String = "SELECT * FROM Table1"

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load


        Conn.Open()
        Dim DataAdapter1 As New OleDbDataAdapter(SQLstr, Conn)
        DataAdapter1.Fill(DataSet1, "Table1")
        Conn.Close()

        TextBox1.DataBindings.Add("Text", DataSet1, "Table1.Name")
        TextBox2.DataBindings.Add("Text", DataSet1, "Table1.City")
        TextBox3.DataBindings.Add("Text", DataSet1, "Table1.Mobile")
        DateTimePicker1.DataBindings.Add("value", DataSet1, "Table1.tdate")
        DateTimePicker2.DataBindings.Add("value", DataSet1, "Table1.ttime")



        ChangePosition()
    End Sub

    Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click
        Me.BindingContext(DataSet1, "table1").Position = 0
        ChangePosition()
    End Sub

    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        Me.BindingContext(DataSet1, "table1").Position -= 1
        ChangePosition()
    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        Me.BindingContext(DataSet1, "table1").Position += 1
        ChangePosition()
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Me.BindingContext(DataSet1, "table1").Position = Me.BindingContext(DataSet1, "table1").Count - 1
        ChangePosition()
    End Sub
    Public Sub ChangePosition()
        Label4.RightToLeft = Windows.Forms.RightToLeft.Yes
        Label4.Text = "السجل " & Me.BindingContext(DataSet1, "table1").Position + 1 & _
        " من " & Me.BindingContext(DataSet1, "table1").Count '- 1
    End Sub

    Private Sub Button5_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button5.Click
        Dim frm2 As New Form2
        frm2.Show()
        Me.Hide()
    End Sub

    Private Sub Button7_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button7.Click
        If MsgBox("هل تريد حذف السجل الحالي", MsgBoxStyle.OkCancel) = MsgBoxResult.Cancel Then
            Exit Sub
        End If

        Dim SavInto As New OleDb.OleDbCommand
        Dim DataAdapter1 As New OleDbDataAdapter(SQLstr, Conn)
        SavInto.Connection = Conn
        SavInto.CommandType = CommandType.Text
        SavInto.CommandText = "DELETE FROM Table1 WHERE Mobile ='" & Trim(TextBox3.Text) & "'" '




        Conn.Open()
        SavInto.ExecuteNonQuery()
        DataSet1.Clear()
        DataAdapter1.Fill(DataSet1, "Table1")
        '    SavInto.Dispose()       '  nezar
        Conn.Close()

        TextBox1.DataBindings.Clear()
        TextBox2.DataBindings.Clear()
        TextBox3.DataBindings.Clear()
        DateTimePicker1.DataBindings.Clear()
        DateTimePicker2.DataBindings.Clear()

        MsgBox("تمت عملية الحذف في قاعدة البيانات بنجاح")

        ChangePosition()


    End Sub

    Private Sub Button6_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button6.Click
        Dim frm3 As New Form3
        frm3.TextBox1.Text = Me.TextBox1.Text
        frm3.TextBox2.Text = Me.TextBox2.Text
        frm3.TextBox3.Text = Me.TextBox3.Text
        frm3.Label4.Text = Me.TextBox3.Text
        frm3.Show()
        Me.Hide()
    End Sub

    '  Private Sub Button8_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)
    '  Dim frm4 As New Form4
    '     frm4.Show()
    '    Me.Hide()
    ' End Sub

    Private Sub Button10_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button10.Click
        Application.Exit()
    End Sub

    Private Sub Button9_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button9.Click
        Dim m As String
        m = "برنامج منبه المواعيد" & vbCrLf
        m &= "هذا البرنامج من اعداد" & vbCrLf
        m &= "المهندسه " & vbCrLf
        'm &= "engauday@hotmail.com"
        MsgBox(m)
    End Sub

End Class