The PlayStation Network will be undergoing some scheduled maintenance tomorrow, lasting for a hour and a half. As usual, no information on the maintenance was divulged, except that it would take place between 4:00pm and 5:30pm GMT on February 16th 2010. During the downtime you will not be able to sign into any PSN services (account management, PlayStation Store, forums etc).
Yaster, the Community Moderator on the PlayStation Forums,:
Just to give you all a heads up, the PlayStation Network is going to be having a bit of downtime on Tuesday the 16th of February.
It will commence at approximately 1600 GMT and should end at 1730, an hour and a half later.
During this time you will not be able to sign in to all PSN services. This includes PlayStation Store, Account Management on all PS products (PS3, PSP, Media Go) as well as our forums, blogs and other websites.