Do yourself a huge favor and check your internet connection and your router. I also have received the same error numerous times in the past and every time it had to do with the problems I just mentioned.
This is what I get when I try to log into PSN:
"An error has occurred. You have been signed out of PLAYSTATION Network (8002AA08)"
I have been getting this ever since I downloaded the new update last night. The internet browser on my PS3 works fine, so obviously the connection isn't the problem. Is anyone else having this problem? Should I wait it out and see what happens or should I contact Sony?