Login not working on mobile devices

Howdy fellow MODxers!

I have a new site which is running on an nginx server. I'm using a modified version of login and am processing the login via ajax. On regular desktop browsers logging in works perfectly well. Logging in works using the login snippet as well as logging into the manager. On iPhone and iPad I can't login to the front-end of the site OR the backend. The front-end gives me a redirect error too.

I'm thinking that there's some server setting I need to set properly. When on the development server (apache, running cPanel) everything worked great. Now, not so much. Anyone have any ideas?

Thanks!