Insert empty billing info into DB

I guess I'm looking for pointers as to how to track this one down. Here's the story - I have an already up and running Drupal 6.10 website that I'd like to add Ubercart to. I copied the entire site to a development box and tested to make sure it's complete. Then I installed Ubercart 6.x-2.0-beta5 including the recommended modules and patched for the Image module issue. Created a catalog with 3 products, set attributes/options for each product and uploaded images. At this point everything looks great - images are as expected, products show up as expected. Select items and place in cart and proceed to checkout. Here's where it's an issue - I fill out the form for billing information and select payment option (check) and then click to review the order. On the next screen the delivery information is blank - no name, address, nothing. The checkout items and total amount follow but not anything that relates to billing, payment, or delivery information.

Next I created a new Drupal 6.10 website - totally barebones and installed Ubercart. Created one product (no images, no "helper" modules installed) and placed an order. Everything worked as expected. OK - so I'm thinking module conflict. I then turned off all extra modules in my first installation (did not de-install) and tried running the test again. Same problem - no delivery or billing information.

I took a look at the DB calls and here's what I see. On the "bad" installation the order of calls is:

UPDATE uc_orders setting the order total
DELETE from uc_order_products based on orderid
INSERT into uc_order_products - the products I'm ordering

The "good" installation DB calls look like this:

INSERT into uc_orders a basic record
UPDATE uc_orders updating the billing and delivery information
DELETE from uc_order_products based on orderid
INSERT into uc_order_products - the products I'm ordering.

So clearly we're not hitting that portion of the code which updates the order record with billing information.

I have tried logging in as different users, used different browsers, cleared caches, deleted cookies and yet I can't seem to get this to work properly with the copy of the existing website.

Any ideas?

TIA,
Betsy