please see the attached Files (XML as the original how it is direct from LifeCycle Designer – and reader.pdf as it is after saving the PDF as a Reader Extended PDF).
As you see, the items that can be added and Removed (Products with dropdown lists and textboxes), are shown 5 times after saving with the extensions. but initially it should be shown only once.
Also when manually removing the 4 other "products" and save as new filled in file, the boxes appear again when reopening.
WHY? i cant figure it out and like to avoid to build the entire form again.
Simply make sure to name each items differently, Adobe has an issue where he thinks a different object with the same name is a different instance and will create the number of instances that he finds with the same name.
The first image is how you named all objects:
This second image is how I renamed all objects, then Acrobat Reader didn't duplicated the issue.
Hope this will help.