Check in this forum for the options you need to specify for your router (for example: B/G only, SSID broadcasted, try WEP (or nothing) first). I have had success connecting with my DIR-655, but eventually replaced it because connections would drop every once in a while, even with the most recent firmware update available. If you follow the recommendations, you should at least be able to get it to work, maybe even with WPA (in my case, WPA was not a reliable alternative with the D-link). After that, check for longer-term connection reliability.

Hope this helps.

Paul