Report saved in pdf is not refreshed

[myaccesss]

From within a Form I launch a report.
In the report there is a button for saving it in pdf format (like c:\Documents\PhotoInventory-20160222.pdf)
When launching the report a second time with a different SQL Where clause, it's properly showed on screen with his new content.
When clicking again the save button ...-20160222.pdf (should be) killed and a new file with the same name (should be) created.
However, it's content is that from the 1st run. It continues this behavior on and on.
What's also weird : there is a timestamp in the report. The timestamp is earlier than the timestamp in the file's properties.
And this timestamp does not change (even hours later).
This is the sourcecode(without error handling) concerned :

Public Function BuildFileName(MyName As String, MyExtension As String) As String
Dim strPath As String
Dim strFile As String
Dim strDate As String
strDate = format(Now(), "yyyymmdd")
strPath = DocumentPath()
strFile = strPath & "" & MyName & strDate & "." & MyExtension
If Dir(strFile) <> "" Then
SetAttr strFile, vbNormal
Pause (1)
'Kill strFile
'Dim fso
'Set fso = CreateObject("Scripting.FileSystemObject")
'fso.DeleteFile (strFile)
End If
BuildFileName = strFile
End Function


Private Sub btnPdf_Click()
Dim strFile As String
strFile = BuildFileName("PhotoInventory-", "pdf")
DoCmd.OutputTo acOutputReport, Me.Report.Name, acFormatPDF, strFile, True
DoCmd.Close acReport, "PhotoInventory"
End Sub

When using the Kill command, sometimes I get an error 75. When using the Fso I always get an error 70.
So in the meantime I delete the saved pdf between 2 runs by hand.
It seems that the first report is buffered somewhere in memory and is all the time created again.
The drive is virus free.
Any suggestions for debugging ?

[rpeare]

I'd use filesystemobject commands to check for the existence of the file first, if it's there delete it, then run your outputto command. It's likely the file will not be deleted or overwritten if access still thinks the file is open as well, even if you don't see it open in your task bar check your START > TASK MANAGER > PROCESSES you may notice instance of your .pdf viewer open and that may be a problem with not correctly closing your objects in your code.

[myaccesss]

As I always closed by DoCmd.Close acReport and I had no such problems with similar code for saving in xls format,
I changed my default Microsoft PDF reader into the Adobe reader.
Now the reports are showed in the reader as expected.
So my conclusion is that Microsoft Pdf reader kept the report content somewhere and for along time in cache.
I even do not need to delete an existing file with the same name (by kill or fso) as the existing file is overwriten by a new one
without any warning.
Thanks for helping me.