Autosave Filename and Directory Issue

I am attempting to use PDFCreator's AutoSave mode in a larger application using the COM interface from C#/.NET.  Some of the time, PDFCreator doesn't respect the options I give it regarding AutoSave filename and directory; the file ends up in my Documents library, with a date/time filename (ie, "20130705070827.pdf").

Do you have any advice for forcing PDFCreator to honor the Autosave Directory and Filename?  

Windows 8, PDFCreator v1.7.0

Relavent code:

    PDFCreator.clsPDFCreator _PDFCreator = new PDFCreator.clsPDFCreator();

    String parameters = "/NoProcessingAtStartup";
    if ( !_PDFCreator.cStart( parameters, false ) )
// Close the existing instance and re-open a new one
ClosePDFCreator( _PDFCreator );

if ( !_PDFCreator.cStart( parameters, false ) )
return false;

    _PDFCreator.set_cOption( "UseAutosaveDirectory", 1 );
    _PDFCreator.set_cOption( "AutosaveDirectory", Path.GetDirectoryName( sFullPath ) );
    _PDFCreator.set_cOption( "AutosaveFilename", Path.GetFileNameWithoutExtension( sFullPath ) );
    _PDFCreator.set_cOption( "AutosaveFormat", 0 );
    _PDFCreator.set_cOption( "AutosaveStartStandardProgram", 0 );
    _PDFCreator.set_cOption( "UseAutosave", 1 );
    _PDFCreator.cPrinterStop = false;
    System.Drawing.Printing.PrintDocument pd = OtherComponent.GetPrintDocument();
    pd.DocumentName = Path.GetFileNameWithoutExtension( sOutputFile );
    pd.PrinterSettings.PrinterName = "PDFCreator";

Thank you!

--Chris W.