I have an Infopath form that I have created and published to a
Sharepoint site using Infopath.  I added 2 columns from the Infopath
form to the Sharepoint site (Customer and Project).

After making some enhancements to the original Infopath form, I
republished it to Sharepoint, overwriting the existing form library.
All the data disappeared from the Customer and Project columns from the
previous forms!  However, when I submit new forms, the data is
populated in the specified fields as expected.

Couple of Questions:
1.  Why do the columns seem to reset/disappear once I republish the
form to Sharepoint?
2.  Is there a way to populate these Sharepoint columns from old forms?
3.  When I republish this form, how can I keep the data in the columns?

Thanks so much for any help you can give!!