Jumping Backwards in a Branching Aware Course

Here's a good one for the Captivate gurus who understand the guts of the program.

In a previous post, Percent scored versus points   I was having a problem with a branching aware course and scoring with a percentage vs. raw points.  The problem has been resolved, but here's the new one:

After my learner completes the end-of-course quiz, if they fail it I'd like to be able to send them back to the content to review and then try the quiz again.  But, whenever I attempt to use an  advanced action to do this:

The percentage calculations for the quiz score, generated by both the "Accuracy" on the results slide and the "cpInfoPercentage" variable, displays not-a-number (NaN).  In my "non-branching-test" I'm able to send the learner back to review the content (i.e. the entire course) which would seem to be more productive then just having them retake the quiz over and over....but that seems to be my only option with branching aware.

Does anyone have any ideas about how to get around this?

Thanks.

Jay