I can only recommend you, to login to you router and that way, compare settings for wi-fi security, with the ones that are on your phone, and see if you missed something.

In some cases it might be that you need to enter the hexed key directly, instead of the passphrase you used on you router. F.ex when you activate WEP security on the router, you can enter a passsphrase like "cheese" and then it generates a hex-key wich is the real key to enter the router. Entering such a key directly when accessing my wi-fi has proven alot of success when i had problems connecting to a wi-fi.