Thanks for reporting this problem. I just looked into it and I think I found the fix.
Edit the /ClientScript/ckeditor-mojoconfig.js
look for the commented out line like this:
//config.allowedContent = 'true';
uncomment it and remove the quotes from around true so it looks like this:
config.allowedContent = true;
You may have to refresh the edit page a few times to make sure it reloads this js file.
The newer version of CKeditor has very strict content filtering on by default and this change turns that off.
Hope that helps,