I am filling out an editable PDF form in Adobe Acrobat 8 Professional. When I save the PDF and fax via Hylafax, the form is blank on the receiving end. I opened up the saved PDF form with Acrobat again and verified that the fields were indeed filled in. When I print the form to PDF, then save with a different name, and fax it, then the contents are visible on the receiving end. Why do I have to print my form to PDF and then save it in order for Hylafax see the filled in contents?