I have a PS3 that I connect on a university network. I have used this network for about 3 months with no trouble. About a week ago it stopped connecting. I set up using the wireless network, easy setup. The signal is strong (about 80%) and the PS3 always detects the signal, but when I try to detect the network it will say it failed to get an IP address, give me error code 801313E, and say it failed to connect to the access point. I can't change the router because it's controlled by the college, but I feel like there must be something I can do on the PS3 settings so that I can still connect. The network does not use any particular security, it's an open network that anyone can connect to, so it isn't an issue of passwords or security protocols I'm not compatible with. There is no way to connect to this network with a wired connection, but my laptop connects wirelessly with no problems. Is there something I can try to fix this?
If the problems started after you installed the 4.0 update, I had the same problems. I finally decided to go against my better judgment and download the update again on a USB key. I reinstalled the update via USB key on the PS3 and I could connect again. Not sure Sony tech monkeys wouldn't suggest this, but when you're desparate, you're desparate. I hope this works for you, mate.
Take the link, download the update to a USB key and install on your PS3 - just follow the instructions. Good luck!!