Errors when attempting to extend features in Acrobat Pro

I just created a form using LiveCycle Designer ES4.  When I save the form, then go and open it in Acrobat 9 Pro to extend features (for the sake of being able to enter information and save the form), I receive numerous error messages - all the same - "Unrecognized namespace XFA 3.3, defaulting to XFA 2.8".  What causes this error, and how can I fix my form so I don't receive it when extending features in Acrobat Pro 9?

This is the first form I created in ES4.  I previously used Adobe LiveCycle Designer ES 8.2 and this error never occurred.

Thanks!