Another note to self…
When you turn off GoDaddy hosting’s previewdns mode, the Joomla admin panel still directs you to http://support.previewdns.com/ anytime you apply a change, click cancel, etc. Clearing the Joomla cache, the browser cache, or switching browsers has no effect.
To correct this, you need to edit the configuration.php file in your root install directory. Edit the var $live_site = to remove the reference to previewdns.com. You may need to change the permissions on this file before editing to allow write permissions for the owner, as it is read only by default (change it back after you’ve edited for safety).
Strangely this fixed some other perplexing problems I’d been having. While still in previewdns mode, I had tried configuring forms using both Chronoforms and Jforms. The drag and drop interface appeared broken in both. After ruling out browser issues, I concluded that there was something about preview mode that caused these to not work. So I told my client that I’d have to wait until the site was live to create the contact form. But, after the site was live, these form components still failed to work. Turns out that correcting the var $live_site corrected this immediately.