error: unable to cast com object

با سلام
من برای ریختن یک فایل متنی به جدولم در sql 2000 از کدی شبیه کد زیر استفاده کردم

Dim oPackage As New DTS.Package2()
Dim oConnection As DTS.Connection
Dim oStep As DTS.Step2
Dim oTask As DTS.Task
Dim oCustomTask As DTS.BulkInsertTask
Try
oConnection = oPackage.Connections.New("SQLOLEDB")
oStep = oPackage.Steps.New
oTask = oPackage.Tasks.New("DTSBulkInsertTask")
oCustomTask = oTask.CustomTask
With oConnection
oConnection.Catalog = "pubs"
oConnection.DataSource = "(local)"
oConnection.ID = 1
oConnection.UseTrustedConnection = True
oConnection.UserID = "Tony Patton"
oConnection.Password = "Builder"
End With
oPackage.Connections.Add(oConnection)
oConnection = Nothing
With oStep
.Name = "GenericPkgStep"
.ExecuteInMainThread = True
End With
With oCustomTask
.Name = "GenericPkgTask"
.DataFile = "c:\dts\authors.txt"
.ConnectionID = 1
.DestinationTableName = "pubs..authors"
.FieldTerminator = "|"
.RowTerminator = "\r\n"
End With
oStep.TaskName = oCustomTask.Name
With oPackage
.Steps.Add(oStep)
.Tasks.Add(oTask)
.FailOnError = True
End With
oPackage.Execute()
Catch ex As Exception
MsgBox("Error: " & CStr(Err.Number) & vbCrLf_
& Err.Description, vbExclamation, oPackage.Name)
Finally
oConnection = Nothing
oCustomTask = Nothing
oTask = Nothing
oStep = Nothing
If Not (oPackage Is Nothing) Then
oPackage.UnInitialize()
End If
End Try


اما وقتی اجرا می کنم error زیر را می ده :
unable to cast com object of type 'system._comobject' to 'dts.customtask

اگه بتونید کمکم کنید ممنون می شم