"Access is denied." errors composing email (using CKeditor) under IE11, cannot insert image/link

Cannot insert images or links into a message that I type in a CKeditor box. When I click on the 'Link' or 'Image' buttons, the dialog pops up, but cannot be closed (either with OK, Cancel or X). On the Upload tab of the dialog, instead of a 'Choose File' button I see a scroll bar that doesn't do anything.

IE's F12 debugger reveals that an "Access is denied." error occurs, producing a stacktrace, when the 'Image' or 'Link' buttons are clicked. This only happens in IE11 to our knowledge. Tested OK in IE10 and Chrome. Replicated on 4.4 and 4.5 demo.

Compatibility View is not a satisfactory solution. If I add the site to Compatibility View while at civicrm/activity/email/add, it appears the 'Choose File' button appears but then 'Send it to the Server' does nothing. If I add the site to Compatibility View while at civicrm/contact/view, nothing appears when I click the 'Actions ->' button.

I believe this may be the CKeditor bug http://dev.ckeditor.com/ticket/10604

Screenshots and stack trace from IE debugger attached.