OSCommerce One Page Checkout Problems

Hi, We're using OSCommerce 2.2rc2a and One Page Checkout v1.07. Both of these are working together, but with three small problems we need correcting: 1. When customers enter different billing and delivery addresses, both appear as the billing address in the admin panel. 2. Occasionally, when a visitor creates an account by entering a password at checkout, they're unable to log back in until they've reset their password. We have not been able to produce this problem ourselves, but have had several complaints from customers. 3. If an entry box is left blank when entering card payment details, a PHP error is displayed when pressing the Continue button. Thanks