All anti virus programs have false alerts. None of them are 100% accurate. What you need to do is contact Norton and send them the manager files and ask them to update their software to remove this false alert. Or you could simply exclude manager from the scanning program.
I am interested in the fact that Manager wants to connect to the Internet. I cannot think of any reason why Manager would need to do this as it currently does not check for latest update, so not sure what it is doing. Interesting. Thats a question for the developer @lubos