If many of you own the older two generations (ie. not the slim) then you probably are experiencing the same error as me. I get on the PS3 and noticed my date was 12.31.1999(OMG Y2K). And some of my save files, trophies, and music have disappeared. And much to my discontent what ever i tried didn't seem to help me sign on. Did a connection test, tried signing on over and over again but to no avail. More can be read on the article i will link
http://ps3.ign.com/articles/107/1072875p1.html
February 28, 2010 - SCEA is looking into widespread reports tonight of PlayStation Network login errors causing many left unable to play games, and even lose trophies, on certain PlayStation 3 consoles.
"We're aware that many of you are having problems connecting to PSN, and yes, we're looking into it," the company said in a statement. "Stay tuned for updates."
Forum members and e-mail tipsters are saying this problem is primarily affecting owners of the older model of the PlayStation 3, and is even causing users to lose trophies previously earned. Many titles, such as Heavy Rain, are also now unplayable due to connection issues with Sony's servers.
One theory points to an issue with the console's internal calendar, which is reportedly resetting pre-slim models to 12/31/1999.
It's unclear at the moment how widespread this issue is.
IGN has contacted SCEA for additional updates on what's causing these errors.
Update: SCEA has confirmed PS3 Slim models (120/250GB) are connecting normally.