corrupted file- result of output of VBA code

I have an excel with VBA code that allows users to click a button to save the created report to an normal excel file without all the macros and code.

They use Excel 2007 and I use Excel 2010- works fine for me- but they get a corruption when they try to reopen the report file. I get a corruption as well when I try to open a file they have created- is there anyway to tell what is causing this corruption?


Code is:

Dim newWb As Workbook, wbFileName As String
       Set newWb = Workbooks.Add
    wbFileName = Application.GetSaveAsFilename( _
    fileFilter:="Excel  Workbook (*.xlsx), *.xls")
    If wbFileName <> "False" Then
        newWb.SaveAs wbFileName
    End If

Corrupted file is attached