I posted this on another thread. It seems to have worked for me at least, I went into settings>notifications and for everything I had in notification centre, I turned off 'view in lock screen', exited settings and then went back in and turned them back on. Since then I've been getting a few notifications which I wasn't getting before, mostly facebook but also mail. I don't think I've been missing any since I did this but it may be a bit early to say.