[5分]找不出原因的难道！

Private Sub cmdRec_Click()
    On Error GoTo ErrorHandler
    Dim strsql As String
    Dim cnn As ADODB.Connection
    Dim rst As ADODB.Recordset
    Dim rstTmp As DAO.Recordset
    Dim blnTransBegin As Boolean
    Dim strExpr As String



    '以下是检测窗体的状态是否改为已接收
    If Me!Status <> "已接收" Then
        MsgBox "接收前要确认资料无误,并将态设为'已接收'!", vbCritical, "提示"
        Me.Status.SetFocus
        Exit Sub
    End If


    '以下是为检测是否已接收，防止两个人同时打开并接收
    If DCount("*", "tbl_Wip_Wo_Dep_Master", "TrCode= '已接收'") > 0 Then
        MsgBox "已接收，不能重复接收!", vbInformation, "提示"
        Exit Sub
    End If


    '检查必填项未通过时退出
    If Not CheckRequired(Me) Then Exit Sub


    Me.cmdRec.Enabled = False




    DoCmd.SetWarnings False


    DoCmd.RunSQL " INSERT INTO tbl_Wip_Wo_Dep_Stock(WoCode, Dep)" _
               & " SELECT Temp_tbl_Wip_Wo_Dep_Detail.WoCode, '" & Me.ToDep & "'" _
               & " FROM Temp_tbl_Wip_Wo_Dep_Detail;"


    DoCmd.SetWarnings True
    Set cnn = GetADOConnection()
    cnn.BeginTrans
    blnTransBegin = True

    cnn.Execute " UPDATE tbl_Wip_Wo_Dep_Master SET Status= '" & Me![Status] & "'" _
              & " WHERE TrCode='" & TrCode & "'"   ', lngCount

    Set rstTmp = CurrentDb.OpenRecordset("Temp_tbl_Wip_Wo_Dep_Detail")


    rstTmp.MoveFirst
    
    Do Until rstTmp.EOF
        cnn.Execute " UPDATE dbo.tbl_Wip_Wo_Dep_Stock" _
                  & " SET Quantity = IsNull(dbo.tbl_Wip_Wo_Dep_Stock.Quantity ,0)- " & Nz(rstTmp!Quantity, 0) _
                  & " ,GrossWeight = IsNull(dbo.tbl_Wip_Wo_Dep_Stock.GrossWeight ,0)- " & Nz(rstTmp!GrossWeight, 0) _
                  & " ,StoneWeight = IsNull(dbo.tbl_Wip_Wo_Dep_Stock.StoneWeight ,0)- " & Nz(rstTmp!StoneWeight, 0) _
                  & " ,NetWeight = IsNull(dbo.tbl_Wip_Wo_Dep_Stock.NetWeight ,0)- " & Nz(rstTmp!NetWeight, 0) _
                  & " WHERE Dep = '" & Me!FromDep & "' and WoCode='" & rstTmp!WoCode & "'"




        cnn.Execute " UPDATE dbo.tbl_Wip_Wo_Dep_Stock" _
                  & " SET Quantity = IsNull(dbo.tbl_Wip_Wo_Dep_Stock.Quantity ,0)+ " & Nz(rstTmp!Quantity, 0) _
                  & " ,GrossWeight = IsNull(dbo.tbl_Wip_Wo_Dep_Stock.GrossWeight ,0)+ " & Nz(rstTmp!GrossWeight, 0) _
                  & " ,StoneWeight = IsNull(dbo.tbl_Wip_Wo_Dep_Stock.StoneWeight ,0)+" & Nz(rstTmp!StoneWeight, 0) _
                  & " ,NetWeight = IsNull(dbo.tbl_Wip_Wo_Dep_Stock.NetWeight ,0)+" & Nz(rstTmp!NetWeight, 0) _
                  & " WHERE Dep = '" & Me!ToDep & "' and WoCode='" & rstTmp!WoCode & "'"


        cnn.Execute " UPDATE dbo.tbl_Wip_Wo_Dep_Stock SET DepDate = " & Format$(Me![UpdateTime], "\'yyyy-mm-dd hh:nn:ss\'") _
                           & " WHERE WoCode = '" & rstTmp!WoCode & "' AND Dep='" & Me![ToDep] & "'"


        rstTmp.MoveNext
    Loop


    rstTmp.Close


    cnn.CommitTrans    '提交事务
    blnTransBegin = False    '事务提交或回滚后要立即恢复标志变量，防止后面的代码出错造成错误代码不能正常判断
   

    MsgBox "保存成功！", vbInformation, "提示!"


    Call ChildFormRequery(strExpr)
    DoCmd.Close acForm, Me.name


ExitHere:
    Set rstTmp = Nothing
    Set rst = Nothing
    Set cnn = Nothing
    Exit Sub


ErrorHandler:
    If blnTransBegin Then
        cnn.RollbackTrans       '出错时如果已启动事务，则回滚撤销
        blnTransBegin = False
    End If
    MsgBox Err.Description, vbCritical, "Error #" & Err
    Resume ExitHere

End Sub

各位大师能看得出以上的代码有什么问题 吗？有时偶尔出现重复运行计算库存！