Re: "File has been changed ... save ?"
Can you post an exact message? There's no such message in WinSCP. There are two similar messages. But they are shown is very different situations. So I want to clarify which of them do you mean:
Or none of these?
The remote file has been changed while you were editing it. Do you want to overwrite it anyway?
File was modified. Save changes?
Or none of these?