I have searched for an answer to this issue, but all related topics pertain to the Domain Mapping plugin which we do not use.
I recently noticed that our parked domains are no longer forwarding properly. They are now being redirected to the signup page. We use cpanel and had managed redirection of two domains to point to our wpmu install. I notice now this no longer works as expected.
For instance, we had domain.org set to forward to domain.com. But if we try it now we get the following result...
...//domain.com/wp-signup.php?new=domain.org
See for yourself: http://tripawds.org
I'm not sure how long this has been going on, or why. Our datacenter (Server Beach) recently merged some DNS services, but I don't see how that could be the cause. NOTE: I did recently rename wp-signup.php and update all the necessary core file links (not reflected in the sample URL provided above) as an anti-splog tactic. But registrations have been working perfectly.
Any thoughts are greatly appreciated. Thank you!