Presentation in trial version of 09 won't upgrade to '13!

I created two eLearning modules (in the same folder) successfully using the 30 day trail version (Presenter '09). Today I purchased Presenter '13 and only one module will upgrade when I want to Preview. The other one gives this message "This presentation was created in an earlier version...would you like to upgrade?". When I select Yes, a message appears "The presentation could not be upgraded. The backup copy will be restored" and I cannot  Preview the presentation. If I select No to the upgrade option, it still won't allow a Preview.

Help!