AICC Completion Tracking Intermittent Failure

We publish Articulate Presenter '09 course that are set to track complete if users pass a quiz at the end of 80% or more. We have several courses that users have sent us screen shots of passing scores but the course does not track aas complete it remains In Progress. A majority of users are tracking correctly. Our LMS is SuccessFactors 6.4 SaaS and we have checked that the courses are set up correctly. The publish settings are set to track Passed/Incomplete and Completed/Incomplete both have users reporting this issue.

I have used the debug feature outlined in the LMS troubleshooting guide and collected information from users but this information comes back with:

AICCComm - LMS Response=ERROR=0 ERROR_TEXT=Successful VERSION=2.2 

I do not have at this point a good idea of the source of the issue. Are there are ideas of what else I can do to troubleshoot this? How would you go about replicating the issue? I have not been able to do this at my desktop or test systems, courses always track for me.

SuccessFactors support are looking on their end, but they agree that we need more information on this.

Any help or suggestions would be greatly appreciated.