Whenever I accidentally access an improper URL on my Omeka installation, I get a "Fatal error: Uncaught exception 'Zend_Controller_Dispatcher_Exception". I'd like to make this a custom 404/Page not found page. Any advice how to do this?
Do you have debugging turned on? That causes exceptions to be displayed on the screen instead of swallowed by the system. If you turn debugging off then 404 pages will automatically go to the 404 page in your theme. You can turn debugging off by opening up application/config/config.ini and making sure that debug.exceptions = false. If debugging is already turned off, then make sure you have a 404.php page inside an 'error' folder in your theme. Let me know if any of that helps.