Thanks again!
I have looked into the registry and did not find any duplicate entries for Bitdefender.
Thinking outside the box:
The version of Bitdefender I have installed (Windows 8 Security) is supposed to be expressly designed for Windows 8 and not just compatible with Windows 8.
Could Bitdefender then be accounted twice, once for the Desktop and once for the Modern UI?
If so, it would still not explain why one antispyware entry is shown enabled and the other disabled.
Maybe your developers can come with an answer!
I look forward for the Security warning workaround!