[Plugin: Advanced Custom Fields] Media library items are missing "insert into post" button

When a user uploads an attachment in an ACF WYSISYG area, it loses the insert into post button because the ACF CPT doesn’t support the editor. While this is not the fault of your plugin, this is causing concern and confusion among clients. I’ve solved this previously in the admittedly-hacky way of adding the editor when registering the CPT but then hiding it with JS.

See Trac ticket http://core.trac.wordpress.org/ticket/18912 (and possibly others).

http://wordpress.org/extend/plugins/advanced-custom-fields/