I'm not sure if this is a bug yet so I'm posting here first. Besides I'm already over my head in this. I've manually applied the following fixes and the problem is still there:
'nodeName' is null or not an object fckeditorcode_ie.js, line 33 character 6143 --> if (e.nodeName.IEquals('input')&&e.type.IEquals(['radio','checkbox'])&&!e.disabled)
The editor works fine when I enable compatibility view and also in Firefox. The page being edited contains only basic html tags so I'm totally dumbfounded.