Just like PrairieFire said Nothing wrong with Netdiscover, I believe this after I tried on my Ethernet card.
When I run the Netdiscover on the Wireless, I don't always get error, most of time there is no problem (Command line or KDE menu). Even I got the error message, I can always reboot my LiveDVD and get Netdiscover to work again. So somehow I guess the problem is from either driver loading issue, or hardware compatibility issue. (And I sure there is no ISO DVD burning issue)