To be able to save a PDF Document in Adobe Reader, you must use Adobe Acrobat Pro and Enable Additional Features
1. ► Open your form in Adobe Acrobat pro
2. ► File ► Save As...► Reader Extended PDF ► Enable Additional Features
3. ► Save your PDF with another name to keep the original
or else you will have an annoying message in Livecycle opening a PDF with Enable Additional Features saying that you have to remove it to be able to edit the form.