sending data via ajax https problem


I have a mailing list form that allows people to submit their email to be on an email list. It works great on https://mymaindomain/subblog

However if I try to use it fails because it is trying to submit the data via

which does not exist.

looking at the plugins code it looks like it is generating that url to send data on via:

var ajaxurl = '<?php echo admin_url('admin-ajax.php'); ?>';

Wondering if:

A. This is an issue with the domain mapping plugin


B. should some how I be sending the form via:

and if the answer how could I modify the code to achieve that?