AddToFileList not working....

Delphi 7
QPDF 0717

When I merge files using the following procedure I get 1 blank page.  The resulting document has the correct name but no contents.  I've searched in vain for what I'm doing wrong.  I've looked at the Delphi demos and can't see what I'm doing wrong.  I've already searched the forum but there is no sample code to show how to successfully use AddToFileList and MergeFileList. 

I'm still evaluating Quick PDF but this is one of my last hurdles before I buy. 

procedure TAutoPrintMainFormForm.MergeEmailPDFsQPDF ;
var source, destination, pname : string ;
   i : integer ;
   Unlockresult : integer ;
   QPDF : TQuickPDF0717 ;
   groupfolder, problemsfolder, pdftempfolder : string ;
   sFileName, pdfname : AnsiString ;
begin
   try
     QPDF := TQuickPDF0717.Create ;
     UnlockResult := QPDF.UnlockKey(QPDFKey);

     QPDF.ClearFileList(sFileName) ;

     // add pdfs to list for merging
     for i := 0 to EmailPDFsFolderMemo.Lines.Count - 1 do
     begin
       // filename with path
       pdfname := Trim(EmailPDFsFolderMemo.Lines) ;
       QPDF.AddToFileList( sFileName, pdfname );
     end ;