Did you configure both wireless connections (2.4GHz and 5GHz) in the router?
Start by temporarily removing the WPA security and configure both G and N connections. I often include the G and N in the SSID so that I can easily identify which one I'm connecting to.
Once you confirm that they can connect without the WPA security, you can then take the next step and add that back in, but I'd suggest using WPA2 as long as all devices support that level, otherwise drop it down to WPA.
message edited by FishMonger