When we upgraded to 2.8.4 from 2.7 our new post and new page sites on the backend did not load. Editing existing posts work fine. Through trial and error this only occurs with Ozh's Admin plugin and the Faster Image Insert plugin are both activated at the same time. According to bitinn on the Faster Image Insert Forum:
http://wordpress.org/support/topic/289190?replies=9
"thanks sdprogress, i checked ozh' plugin, its a conflict within wordpress core JS libraries, between "schedule" and "farbtastic". A resolution will be to deregister "farbtastic" appropriately, as wp_enqueue_script registers known libraries globally. "
Can I do anything to fix this? I am not sure what that means.
http://wordpress.org/extend/plugins/ozh-admin-drop-down-menu/