One-Page Checkout [Support Thread]

[lat9]

Not that I'm aware of. I took a download of the FEC module and deleted any matching files that existed on the site.

Can you confirm that it's not expected and/or deliberate behaviour for the class names to be getting stripped of the form fields?

Yes, I can confirm. OPC's AJAX processing uses the Zen Cart $template class to load the OPC sub-template modules to render its output.

Are there any debug-logs generated? How about browser's console-logs?

Update: Is the site publicly available for viewing? If so, send me a PM with the link.