One-Page Checkout [Support Thread]

[lat9]

But if the condition was understood correctly, on the initial run through of the hash, wasn't $_SESSION['shipping'] not set to begin with? Thus the first cycle would not have that session variable and then when checking for the change, the extras key would be removed but now the shipping session variable would be present?

I say that because of the fix that appeared to work for the OP.

OPC's AJAX handler sets the session-based shipping. If the overall value isn't set, there'd be a redirect back to the main page prior to the hash.