I have occasionally seen a similar issue where changes to CC text on one slide were replicated across a number of other slides. The issue there seemed to be that the affected slides were created by copying and pasting the same slide over and over again.
Is it possible that this is the way you created the slides in your project? If so, you may be able to resolve the issue by copying all slides (at once this time) and pasting them into a brand new project. This forces Captivate to set up new unique identifiers for all slides and objects.
