Error 4005 by CopyItemToDocument

Hi. I have a following problem.In a PostSave event I have the following script:

Sub Postsave(Source As Notesuidocument)

Dim Workspace As New NotesUIWorkspace

Dim Doc As NotesDocument

Source.Refresh

Set Doc = Source.Document

If Doc.HasItem(“tmpFile”) Then

If Doc.HasItem(“File”) Then

Call Doc.RemoveItem(“File”)

End If

Set tmpItem = Doc.GetFirstItem(“tmpFile”)

Call tmpItem.CopyItemToDocument (Doc,“File”)

Call tmpItem.Remove

Call Doc.Save(True,False,True)

End If

End Sub

It works for the first and second time of running this script, but for the third time and more it throws an error 4005 on the following line:

Call tmpItem.CopyItemToDocument (Doc,“File”)

Can anyone help me to understand what is wrong? This error is being thrown for the third time I save any document, which has that script in PostSave event.

Thanks in advance. Jiri