cracking WPS PIN in 2 hours is unrealistic. It is, and should be, exercise of many hours/days - well, it may sound harsh at the beginning, but considering this or never (try cracking properly set-up wpa2-psk) it's great method of attack. Anyway, I was able to crack wpa2-psk network with WPS enabled, by just leaving device on attack mode for two nights. Which is great, when we think about wpa, let alone wpa2. /Estel