So I have a Drupal Commerce site setup for a client. Yesterday I get a report from the client that registered users lose their cart contents.

I have tested this and here is the process I run across.

• Visit the website
• Log In
• Add any number of items to the cart
• Log Out

- - - - - Any amount of time passes - - - - -

• Re-visit the website
• Log In
(At this point they can see their cart with items in the sidebar block)
• Click "VIEW CART" or "CHECKOUT"
• The site loads a 404 Error page, logs them out, and tosses the cart contents.

- - - - -

The site is a D7 site and we are using secure pages to on checkout/*.
I have searched the issues at D.O and look though the documentation here. I have also done various google searches for some one having a similar issue.

- - - - -

Other items of interest:
• It does not matter what browser is used.

• If in the steps listed above, the visitor adds a new product to the cart BEFORE clicking either view cart or checkout, then everything is fine. Once a new product is added, both the view cart and checkout work as expected and show all previous products as well.

• If a new user creates a cart of items then process the checkout, it works as expected.

• On the same note, if a registered user logs in either before adding items or after/during adding items, everything works as expected.

- - - - -

I have checked every setting, rule, module, etc I can think of and nothing seems to fix the issue.

I'm just looking for some general direction here on what might be causing the issue that I can look into further.

Thank you for your time.