I've got a problem with domain mapping on my multisite installation.
Users cannot comment on posts/pages when the parked domain is set as the primary domain. They can if the site is displaying as a subdomain. (ex broken as example.com and working as mainsite.com/example )
On submitting the comment, there is a 404 when looking for wp-comments-post.php.
I've tried disabling all the other plugins, both WordPress and Domain Mapping appear to be up to date, and I'm just a little out of ideas for troubleshooting this.
The site is here if you'd like to take a look at it.