Fillable forms fields that have been filled with text, then the file is sent, are now blank.

Anyone else experience this?  I've made several forms on a PC with Acrobat Professional 10.  Then, when I open the PDF Form filled document on a Mac, fill in the form fields with content, save and close the file, and then send as an email, when the file is opened on either a Mac or PC the entered content is gone.  Any thoughts