Acrobat 9.4.5.236 - GetJSObject fails on 64-bit Windows 7

Question

My application will raise an error when attempting to get the javascript object reference for a page document.  The code runs fine on a Windows XP client, but not on a Windows 7 Professional 64-bit client.  Has anyone else encountered similar errors, and if so, what is the right step?  Move to Acrobat X?
Here is my VB6 code (application too large to convert to .NET right now):
Function ConvertPDFtoPRN(ByVal lsPDFFilename As String, _
                         ByVal lsInputDir As String, _
                         Optional ByVal liType As Integer = 0) As Boolean
' Take an input PDF file and reprint it to a specific other printer (Xerox WorkCentre Pro 55), directing
' that printer driver to save the output as a file (PRN).  That output is used in a later process to send
' to the stores and is printed via a unix job by simply copying the PRN file to the printer.
    'local variables
    Dim lbRet As Boolean
    Dim lvRet As Variant
    Dim loApp As Acrobat.CAcroApp
    Dim loAvDoc As Acrobat.AcroAVDoc
    Dim loPDoc As Acrobat.CAcroPDDoc
    Dim loJS As Object
    Dim loPrinterParams As Object
    Dim lsTargetPrinter As String
    Dim lsPRNFileName As String
    Dim liPaperSize As Integer
    Dim liDuplex As Integer
    'trap errors
    On Error GoTo ConvertPDFtoPRN_Error1
    'create objects
    Set loApp = CreateObject("AcroExch.App")
    Set loAvDoc = CreateObject("AcroExch.AVDoc")
    Set loPDoc = CreateObject("AcroExch.PDDoc")
    'specify output printer
    lsTargetPrinter = ReadProfileString("PDF", "PrnPrinter", gsINIFile, "Xerox WorkCentre Pro 55")
    'setup file names
    lsPRNFileName = "\" & Replace(lsPDFFilename, ".pdf", ".prn", vbTextCompare)
    lsPDFFilename = lsInputDir & lsPDFFilename
    'open source PDF file
    If loPDoc.Open(lsPDFFilename) Then
        Set loJS = loPDoc.GetJSObject()
        If loJS Is Nothing Then
            loPDoc.Close
            Set loAvDoc = CreateObject("AcroExch.AVDoc")
            If loAvDoc.Open(lsPDFFilename, "") Then
                Set loPDoc = loAvDoc.GetPDDoc
            End If
            Set loJS = loPDoc.GetJSObject
        End If
        'Check the output type
        If liType = 0 Then
            liPaperSize = cPogPaperSize      '1
            liDuplex = 3
        Else
            liPaperSize = cFloorPaperSize    '3
            liDuplex = 1
        End If
        'set output printer parameters
        On Error GoTo ConvertPDFtoPRN_Error2
        lbRet = ChangePrinterSettings(lsTargetPrinter, vbPRCMMonochrome, liPaperSize, , liDuplex)
        On Error GoTo ConvertPDFtoPRN_Error3
        Set loPrinterParams = loJS.getPrintParams()
        On Error GoTo ConvertPDFtoPRN_Error4
        loPrinterParams.PrinterName = lsTargetPrinter
        On Error GoTo ConvertPDFtoPRN_Error5
        loPrinterParams.Interactive = loPrinterParams.Constants.interactionLevel.silent
        On Error GoTo ConvertPDFtoPRN_Error6
        loPrinterParams.FileName = lsPRNFileName
        'print the file
        On Error GoTo ConvertPDFtoPRN_Error7
        lvRet = loJS.Print(loPrinterParams) 'error!
    End If
    'close up
    On Error GoTo ConvertPDFtoPRN_Error8
    Set loJS = Nothing
    If Not loPDoc Is Nothing Then
        loPDoc.Close
    End If
    If Not loAvDoc Is Nothing Then
        loAvDoc.Close (0)
    End If
    If Not loApp Is Nothing Then
        loApp.Exit
    End If
    'success, exit
    lbRet = True
    GoTo ConvertPDFtoPRN_Exit
'error handlers
ConvertPDFtoPRN_Error1:
    lbRet = False
    gAppLog.LogMessage "ConvertPDFtoPRN_Error: " & Err.Description, modName, gsCurModule, ErrorMessage, Err.Number
    Resume ConvertPDFtoPRN_Exit
ConvertPDFtoPRN_Error2:
    lbRet = False
    gAppLog.LogMessage "ConvertPDFtoPRN_Error2 (Change Printer Settings): " & Err.Description, modName, gsCurModule, ErrorMessage, Err.Number
    Resume ConvertPDFtoPRN_Exit
ConvertPDFtoPRN_Error3:
    lbRet = False
    gAppLog.LogMessage "ConvertPDFtoPRN_Error3 (Get Print Parameters): " & Err.Description, modName, gsCurModule, ErrorMessage, Err.Number
    Resume ConvertPDFtoPRN_Exit
ConvertPDFtoPRN_Error4:
    lbRet = False
    gAppLog.LogMessage "ConvertPDFtoPRN_Error4 (Set Printer Name to '" & lsTargetPrinter & "'): " & Err.Description, modName, gsCurModule, ErrorMessage, Err.Number
    Resume ConvertPDFtoPRN_Exit
ConvertPDFtoPRN_Error5:
    lbRet = False
    gAppLog.LogMessage "ConvertPDFtoPRN_Error5 (Set Interactive Silent): " & Err.Description, modName, gsCurModule, ErrorMessage, Err.Number
    Resume ConvertPDFtoPRN_Exit
ConvertPDFtoPRN_Error6:
    lbRet = False
    gAppLog.LogMessage "ConvertPDFtoPRN_Error6 (Set Output FileName To '" & lsPRNFileName & "'): " & Err.Description, modName, gsCurModule, ErrorMessage, Err.Number
    Resume ConvertPDFtoPRN_Exit
ConvertPDFtoPRN_Error7:
    lbRet = False
    gAppLog.LogMessage "ConvertPDFtoPRN_Error7 (Print): " & Err.Description, modName, gsCurModule, ErrorMessage, Err.Number
    Resume ConvertPDFtoPRN_Exit
ConvertPDFtoPRN_Error8:
    lbRet = False
    gAppLog.LogMessage "ConvertPDFtoPRN_Error5 (Cleanup and Exit): " & Err.Description, modName, gsCurModule, ErrorMessage, Err.Number
    Resume ConvertPDFtoPRN_Exit
'exit
ConvertPDFtoPRN_Exit:
    'release objects
    Set loJS = Nothing
    Set loPDoc = Nothing
    Set loAvDoc = Nothing
    Set loApp = Nothing
    'set return value and exit
    ConvertPDFtoPRN = lbRet
End Function

Answer 1

Acrobat is a 32bit app.  Your app needs to be too.