After the current update I have been signed out of PSN non-stop. Sometimes I get a DNS error code and some times I get the code 80028ED4 or 8002AD23. I have tried rebuilding the system database and changing the DNS settings and everything you can think of. I even turned the router off for an hour. I hear a lot of people are having this problem too. I turn on my ps3, it signs in fine then I go to battlefield bad company 2 and there is an error synching trophies then it gives me an error so I go back to the XMB then I get signed out with the DNS error. I tried switching to Google's dns and a lot more and it still does the same thing.