Connection issues

I've gone through the steps to get my ps3 connected after receiving "key information exchange timed out" message, restarted my router, used custom instead of easy. doing the steps in the solution many people give, and yet it still won't work. I've entered all the information manually even though it's not suggested and it still can't obtain the i.p address... even though I typed it in. I just don't understand, it has done this before but on different wi-fi and service provider but eventually worked on that one. now I'm back living with my room mate and it has connected to this very wifi before with zero problems connecting. so, are there any advanced solutions beyond the common one?

p.s it has connected to this very router, wpa, ip, before with zero problems or snags. my thinking is, purely based on lack of any and all understanding, is that perhaps after adjusting to another router and all the information it's having difficulties readjusting back???

I just tried one more time, instead of saying exchange timed out it just failed at the ip part