Crystal Reports won't load in Vista but OK in XP

I have a Windows Form VB.NET application using Crystal XI R2 to produce reports.  The application works flawlessly on other machines in Windows XP, but as soon as I try to load a report in Vista the program exits with the following message -

Description:
  Stopped working

Problem signature:
  Problem Event Name:      APPCRASH
  Application Name:      Manufact.exe
  Application Version:      1.0.0.0
  Application Timestamp:      487ed6c1
  Fault Module Name:      unknown
  Fault Module Version:      0.0.0.0
  Fault Module Timestamp:      00000000
  Exception Code:      c0000005
  Exception Offset:      050e3ed0
  OS Version:      6.0.6000.2.0.0.256.6
  Locale ID:      3081

This happens (only in Vista) whether the report is sent direct to the printer or to the Crystal Report Viewer and occurs at the crReport.Load (direct print) or New CrystalDecisions.CrystalReports.Engine.ReportDocument (viewer) statements.

Despite having Try/Catch blocks and exception handling in place I get no other error messages apart from the above.

I have downloaded and installed all of the CR XI R2 service packs up to SP4 on the development machine.
However, the Crystal redistributable file (CrystalReports11_5_NET_2005.msi  - 79346kb) is still dated 24/02/2006 which doesn't seem right.  

I have searched everywhere on the net and Business Objects sites to resolve this issue but can't find any similar cases or solutions.  Is there another patch to fix Crystal for Vista ?