My PS3 can't find my IP address?

It has never done this before, but about a week ago it wouldn't let me sign in. and it would give me the message "Search for IP address timed out" (or something like that). So I test the internet connection from the PS3. It still can't locate the IP address. I go into the network setup and do the easy setup, put in the WPA code, save the settings (which haven't even been changed), test the connection still can't find the IP (which I was expecting). Go to set up network again, this time choosing Manual setup. Put in the WPA again and choose manual for IP address. Put in the IP address and all the other info. Then for all the other things I just choose automatic (or whatever the default option is) save the settings. Test the connection again, still can't connect to the internet (although it does seem to find the IP address at this point). Set up a network connection AGAIN. this time choosing easy again, put in the WPA code, save settings, test internet connection and it works. and I am able to sign in and everything. But here's the problem, every time I turn my PS3 off and then turn it on again it won't let me sign in again. and I have to do that whole process with the internet connections again (first setting it up manually, having it fail, then doing the easy setup). It works fine after I do that. Can someone tell me how to fix it, so I don't have to go through the internet connection thing everytime? or at least explain why it's happening?