Help needed to connect WiFi on Nintendo DS!?

I have used 'Search for an Access Point' on DS and it finds my Sky Netgear broadband router. The problem occurs when I try to select this - it says the access point's security settings are not supported by the Ninetndo DS. My router has an encrypted WAP key, rather than a WEP key - is this what's causing the problem? I've tried manually setting it up by trying to type in the WAP key but it doesn't allow me enough characters. Is there anyway around this, either on the DS or on my router settings? Or is it better to get a USB connector for the DS - how does this work getting round the security access problem? Any help appreciated!