I don't know that I'll be able to go backwards compatible to IE 8 or not. Theoretically, with the settings I have for loading the editor, you SHOULD be able to. However, testing in different modes for myself, it only looks to be working correctly in IE 9 or higher, standard docs mode. As I'm running Win 7, the OS itself won't actually let me install a lesser version of the browser so I can test further.
Your best bet at this point is to use any other browser than Internet Explorer. The editor works in all the rest without any problems.