Why are my facebook notifications not showing up?

[Cepheron]

My facebook notifications are no longer showing up in my e-mail or up in the top right hand corner where they usually do, you know friend requests, comments, and wall posts. I haven't changed anything at all, they just stopped popping up. Anyone have any idea what is going on, or why it might do that?

[Hayley Cooper]

Go into settings and notifications and look at the options on there

[AlwaysRight]

Lots of people have this problem all of the sudden. Recent Facebook change must have screwed things up. I haven't been getting notifications for over a week, and I've done everything possible to try to fix it. Clearly a bug.