WIA issues on windows 7, works perfect on 8

Question

I have 2 problems,

1) a machine I need to use for debugging will not show the scanners plugged into it in my dialog but will in windows scan and fax, the same scanners show in windows 8 and other win 7 machines.

2) i'm trying to debug why the app crashes when the transfer is called on windows 7 only.

Scan And Fax for windows shows my 2 scanners on windows 7 but using a custom app that implements native WIA in c++ it does not show the scanners in the select device dialog.

This app works fine on windows 8 and some other windows 7 machines although it crashes when doing the transfer with the below crash info.

Problem signature:

  Problem Event Name:                        APPCRASH

  Application Name:                             DocumentImportManager.exe

  Application Version:                           1.0.0.0

  Application Timestamp:                     50f9c275

  Fault Module Name:                          sti.dll

  Fault Module Version:                        6.1.7600.16385

  Fault Module Timestamp:                  4a5bdb14

  Exception Code:                                  c0000005

  Exception Offset:                                00015568

  OS Version:                                          6.1.7601.2.1.0.256.48

  Locale ID:                                             1033

  Additional Information 1:                  0a9e

  Additional Information 2:                  0a9e372d3b4ad19135b953a78882e789

  Additional Information 3:                  0a9e

  Additional Information 4:                  0a9e372d3b4ad19135b953a78882e789

Answer 1

2) is fixed by removing IWiaAppErrorHandler from my callback class. some reason sti.dll was getting access exception after the return of this instance from QueryInterface

1) still happens but the device is there if I enumerate it and not use SelectDeviceDlg