Starting from 4PM on Monday the 4th of march, the PlayStation Network will undergo an 11 hour Maintenance, here is a quote from the source:
During the maintenance, you will be unable to access the following services:
- PlayStation Store on PS3 and PSP.
- PlayStation Network Account Management.
- PlayStation Network Account Registration.
In addition, you will not be able to sign in to PlayStation Network from eu.playstation.com.
During this maintenance, you can continue to collect in-game trophies and these will be updated on your profile once PlayStation Network is back up and running.