Hi,
Did you try the suggestion in article I have posted in previous post? If you open visual studio and go to
~/CMSAdminControls/CKeditor/config.js and add the following lines:
config.protectedSource.push(/<i[\s\S]*?\>/g); //allows beginning <i> tag
config.protectedSource.push(/<\/i[\s\S]*?\>/g); //allows ending </i> tag
it should solve your problem, basically you can place there any tag you want by changing the "i" in the definiton.
Best Regards,
Roman Konicek