I'm having issues with this when trying to use Guest Checkout. At first I thought it was related to my template, but I just tried a fresh install of ZenCart 1.5.7 with Responsive Classic template and a fresh install of One-Page Checkout version 2.3.3
ZC was installed with demo data. I set a random name for moneyorder payment and deleted moneyorder from the disallowed payment methods. Shipping is set as 'Flat Rate'.
When trying to do a guest checkout there is no content in the right column. so nothing related to shipping or payment.

Am I making an incorrect assumption that this should just work out of the box with responsive classic?