汇总多个工作簿中表到一个表中的问题

ylj518

Sub 汇总工作簿中工作表()
Dim filePath, fileName, sht, wb As Workbook, Nam
filePath = ThisWorkbook.Path & "\"
Nam = ThisWorkbook.Name
fileName = Dir(filePath & "*.xls", vbDirectory)
Application.ScreenUpdating = False
Do While fileName <> ""
    Set wb = GetObject(filePath & fileName)
      For Each sht In wb.Worksheets
      sht.copy after:=ThisWorkbook.Worksheets(ThisWorkbook.Worksheets.Count)
      ActiveSheet.Name = sht.Name & "-" & Replace(wb.Name, ".xls", "")
'      ActiveSheet.Name = sht.Name
      Next
      wb.Close
      Set wb = Nothing

    fileName = Dir()
Loop
  Application.ScreenUpdating = True
End Sub
两个要汇总的表是xls,汇总的是xlsm,为什么导入时连汇总的xlsm中的的表也要导入，dir中指明了xls类型。Do While fileName <> nam,虽可解决问题，但指明文件类型为xls为什么会有问题？