Unfortunately I have to ask a pretty vague question, and I can't provide much background because I can't reproduce.
Working on a Drupal 7 Commerce install with Domain Access we are (seemingly) randomly missing shipping and/or billing information on orders. Sometimes the order has a billing name (or shipping name) but no address information. Others, either shipping or billing is completely missing from the order view.
This is happening on ~1% of orders and I can't find any way to link them with consistency. It has happened on PayPal Express Checkout orders, Authorize.net orders, orders with different shipping methods, orders from different domains, etc. The stored API responses from the payment processors are normal.
In testing (on production), I can't reproduce; I've tried both payment methods, anonymous accounts, existing accounts, etc. I can't even get past the Billing/Shipping form without completing all the information, no matter what I've tried.
Hopefully someone has experienced this before; if not, I'm totally open for "try this" or "look here" suggestions.