I just looked into it and ended up googling for the error.
One of the first hits on google was a thread on these forums, specifically the Xniff thread.
So after reading it for a bit I found
CookieRevised's Reply in which he states that this error occurs when a raw socket could not be created. (The rest of the thread might be worth reading too)
Most of the time this problem occurs with wireless devices, but it could also be a driver issue.
/ 
