Notification centre not notifying me

Hi,

Have just installed OS mountain Lio onto my Macbook Pro, however when I go into the notifications centre, there is no notifications from iCal, iMessage, Mail, reminders, twitter. This being said, I have appointments in my iCal, recieve messages daily in iMessage and Mail and have several work related reminders. So can't see creating "tester notifications" to being the solution to it (I have tried this). The only notifications I seem to be recieveing is from facebook.

Other options I have tried is: Deleting icloud account from macbook and turning notification centre off in activity monitor, but still nothing.

My edition of macbook is a 2008 model "Core 2 Duo" 2.0 GHz Processor 4GB RAM.

Could someone help me out here and let me know if it a background programme that is preventing this or if there is other solutions to this.