Oscommerce problem- customers shipping address mixed up

Looking for an osCommerce expert to fix a problem. Problem: Basically, when A person placed an order, there are two orders in our osCommerce. One is right order A, but other one is mixed order B with A name and contact information and B shipping address and billing address. In order B, there is only B mailing address but no phone # and email address. Also, we cannot find any B information in the "customers". Our hosting is Windows. I have changed the Sessions Force Cookie Use True Info Check SSL Session ID True Info Check User Agent False Info Check IP Address False Info Prevent Spider Sessions True Info Recreate Session True I cannot changed check IP address and Check User Agent to true, because it will keep asking customers to logo into their account, and all links will lose from main page to osCommerce If you change IP address and Check User Agent to true, the problem will fixed. Please don't bid if you have no experience of eCommerce.