We are running the latest version of the plugin, 2.40.3. The individual maps display fine in any browser, but the mashup page shows the map only in Firefox. In Safari and Chrome it shows the loading gif and nothing happens. On a PC, Chrome and Firefox work, but IE doesn’t.
Normally that should just return ‘0’, but it’s returning the entire home page (you can try it – just enter it in your browser). Is there some kind of redirect from the theme or another plugin? Or is the AJAX url incorrect?
If that doesn’t help, then it would help if we could rule out conflicts:
1. Deactivate ALL of your other plugins
2. Switch to the standard 2012 theme
3. Go to your ‘permalinks’ settings and save them again (to update the .htaccess file)
4. Check that page again – if the issue seems to be resolved, reactivate until you find the conflict.
The browser behavior was a red herring; we had access to wp-admin disabled in the theme’s functions.php for all but administrators and your call to admin-ajax.php wasn’t working because of that. It worked for me in FF because I was logged in as admin in FF.
We had to install a plugin, WP Admin No Show to get the same functionality without killing access to admin-ajax.php.