Multisite + SSL + Marketpress > redirect loop

I’ve got Marketpress installed at The site is a mapped domain from Everything was working fine EXCEPT some of the elements on the checkout pages were not showing secure, throwing an error to shoppers. I scoured the forums looking for answers and came across


{ define( ‘SUNRISE’, ‘on’ ); }

When I added it – it broke the checkout process. It now goes into a redirect loop and will not work.

I need to get this back up ASAP. Seems this is a recurring problem with Marketpress.