Hi,
I'm using Norton Internet Security and I have 500 days left on my subscription so I really hope you're not right!
So the runtime broker manages memory for applications that do not target the Windows Runtime as well as those that do? I thought it was only for new apps that ran in the metro interface...
I will see if removing NIS makes any difference on my machine but like you, I'll just have to live with it if it does.
I have had some other issues with metro-style apps not starting and reverting to the start menu when I open them but that's probably unrelated to this issue so I won't go into details here. I guess we have to expect a few teething problems although having said that, these kind of problems should have been ironed out before it was RTM'd.