Hi, Im having a similar problem,
I've trying ARP spoofing with both arpspoof and ettercap on BT4.
Im not getting any error messages;
arp -a on target machine indicates that network has been spoofed currectly;
tried with 2 different wireless cards on BT machine;
getting a DOS on target machine, all webpages are timing out;
does anyone have a lead on the problem?