Word 07 doesn't save; To, From, Subj. Used "Send to Mail R..

Using "Send to Mail Recepient" to open the email input area below the menu to
enter email info, ie, To, From, subject, etc. If I then save it as a docx
file and then as a doc file. The next time I open the docx file all the
email info items I added are gone and the subject has changed to the
document's name. If I open the doc file, the To, From, Subject, etc are all
still there.

If I open a doc file with email info it is all there. If I save the file as
a docx file, all the email info is lost.

Any ideas how to get 07 to actually save the email info so it is there when
the file is reopened?