iPhone cannot connect to Wi-Fi only when it is WEP

Okay, I haven't found any topic relating to this issue. If there is such a thread, forgive my error.
So my problem is basically that my iPhone 4 with iOS 5 (previous versions had the same issue) cannot connect to my home Wi-Fi unless:
1, It is not protected by any kind of password
2, It is protrected by WEP. Somewhy my router won't accept the legit ASCII code, only hexadecimal.
Whenever I set the protection to WPA2 PSK, it won't find the network, and even if it does, it keeps telling me that the device was unable to connect to the network.
I have tried forgetting the network, resetting the network information in settings, but so far I haven't found a solution. Any ideas?