Importing data file back into blank PDF - some data fields don't populate




I have created a writable PDF in Adobe LiveCycle 8. Once the form is completed the person filling out the form submits by email. The email is successfully received and the data file is complete (opening it in a browser verifies this). However, when I use try to import the data back into the PDF file (by opening Adobe Pro | blank form | managage form data | import data - only some of the fields are populated. I need this data to repopulate the form so I can print it and I also need to export it to Excel for other purposes. What am I doing wrong?