Domain Mapping conflicting with Events+

we're running events+ and domain mapping on a multisite install. currently, the rsvp list is not working properly. events+ uses admin-ajax.php to query the list of rsvps, but since we are using the domain mapping plugin, it is denied access, because (apparently) admin-ajax redirects back to the original url of the site.

so for example:

when we created a new site, url was:, and we domain mapped to the rsvp button tries to call, but is then redirected to

i suppose that since the domain names are different, as a security feature, access is denied somehow.

any help on how to solve this would be great. i have already tried updating wordpress options siteurl and home, but this creates more problems.