is the playstation network down? i havent been able to sign in since the day before yesterday
Welcome to the Playstation Online Community.
I haven't signed in myself this morning yet but I was online yesterday with no issues, maybe the network is just busy with new PS3 owners or you could try resetting your router / Internet connection, there's no planned maintenance so it's not that.
Maybe you should try going into your network settings on your PS3 and changing the MTU.
Just take it off of automatic (default) and change it to 1490.
I looked around and found that it worked for some people.
Click this link and scroll down and read: http://community.us.playstation.com/thread/3008507