The iOS 3.2.3 ProntoForms release, available on the Apple AppStore as of April 11, 2012 has an issue which may affect some users.
This error may be present when viewing a dropdown or radiobutton type question that is configured to use a lookup:
This message can be safely ignored, and does not indicate a problem with your forms or lookups. We have identified the cause of this error, and it will be fixed with the next release of the ProntoForms iOS client.
We apologize for any confusion and inconvenience this may cause and thank you for your patience.