Anonymous user not logged in after Paypal WPS redirect
I have set up a Drupal Commerce shop with one payment method (Paypal WPS). Using Paypal WPS is difficult enough for users not accustomed to it and I want keep the process on the Drupal Commerce side as simple as possible. For this reason, I don't want anonymous users to have to go through the account registration process in order to make a purchase. They should do the following at checkout:
1. Review Order
2. Enter Shipping Address
3. Get redirected to Paypal on clicking continue.
4. Complete the Paypal form and confirm
5. Redirect back to drupal commerce and see their order confirmation without additional clicks.
The problem is that when the anonymous user is redirected back to Drupal Commerce, they see a page with the following: "Your order is number ####. You can view your order on your account page when logged in." If they click on "view your order" link, they get "Access denied. You are not authorized to access this page." Since I don't want require customers to register on the site (at least not overtly), requiring them to login in order to see their order confirmation doesn't work. It's fine if an account is automatically created without adding extra hoops for the user to jump through like account verification emails, but how can I make it so they are logged in prior to the Paypal redirect so they are already logged in when they come back to achieve #5 above?
Or maybe there is another way to achieve the behavior in #5? I tried disabling the checkout rules, "Assign an anonymous order to a pre-existing user" and "Create a new account for an anonymous order", but I still experience the same problem.
I will really appreciate any assistance.