IPOD Touch/Wireless router?

Ok heres the deal.....I turn on my wifi to my ipod touch to get connected to my router. The only time it works is when I have my security settings set to none on my router. I was told to keep it set at WPA-PSK [TKIP] + WPA2-PSK [AES]. If I keep it on that setting and i go and put in my pword, it said unable to connect to network. Any advice?