i cant get driftnet to work correctly all i get is:

ettercap NG-0.7.3 copyright 2001-2004 ALoR & NaGA

urlsnarf: listening on eth0 [tcp port 80 or port 8080 or port 3128]
Bad argument `?dport$'
Try `iptables -h' or 'iptables --help' for more information.
Bad argument `?dport$'
Try `iptables -h' or 'iptables --help' for more information.
Bad argument `?dport$'
Try `iptables -h' or 'iptables --help' for more information.
Bad argument `?dport$'
Try `iptables -h' or 'iptables --help' for more information.
Bad argument `?dport$'
Try `iptables -h' or 'iptables --help' for more information.
Bad argument `?dport$'
Try `iptables -h' or 'iptables --help' for more information.
Bad argument `?dport$'
Try `iptables -h' or 'iptables --help' for more information.
Bad argument `?dport$'
Try `iptables -h' or 'iptables --help' for more information.
Bad argument `?dport$'
Try `iptables -h' or 'iptables --help' for more information.

sslstrip 0.6 by Moxie Marlinspike running...
Listening on eth0... (Ethernet)

eth0 -> xx:xx:xx:xx:xx:xx 192.168.0.3 255.255.255.0

Privileges dropped to UID 65534 GID 65534...

my /etc/etter.conf file looks like:

#---------------
# Linux
#---------------

# if you use ipchains:
#redir_command_on = "iptables -t nat -A PREROUTING -i %iface -p tcp ?dport$
#redir_command_off = "iptables -t nat -D PREROUTING -i %iface -p tcp ?dport$

# if you use iptables:
redir_command_on = "iptables -t nat -A PREROUTING -i %iface -p tcp ?dport$
redir_command_off = "iptables -t nat -D PREROUTING -i %iface -p tcp ?dport$


i dont know whats causing this error ?

can anyone please help ?