Hi when im running ettercap in root (su) i keep getting this error:
linux-krz3:~ # ettercap -G
ettercap NG-0.7.3 copyright 2001-2004 ALoR & NaGA
iptables v1.4.2-rc1: can’t initialize iptables table nat': Permission denied (you must be root) Perhaps iptables or your kernel needs to be upgraded. iptables v1.4.2-rc1: can't initialize iptables table nat’: Permission denied (you must be root)
Perhaps iptables or your kernel needs to be upgraded.
iptables v1.4.2-rc1: can’t initialize iptables table nat': Permission denied (you must be root) Perhaps iptables or your kernel needs to be upgraded. iptables v1.4.2-rc1: can't initialize iptables table nat’: Permission denied (you must be root)
Perhaps iptables or your kernel needs to be upgraded.
iptables v1.4.2-rc1: can’t initialize iptables table nat': Permission denied (you must be root) Perhaps iptables or your kernel needs to be upgraded. iptables v1.4.2-rc1: can't initialize iptables table nat’: Permission denied (you must be root)
Perhaps iptables or your kernel needs to be upgraded.
iptables v1.4.2-rc1: can’t initialize iptables table nat': Permission denied (you must be root) Perhaps iptables or your kernel needs to be upgraded. iptables v1.4.2-rc1: can't initialize iptables table nat’: Permission denied (you must be root)
Perhaps iptables or your kernel needs to be upgraded.
iptables v1.4.2-rc1: can’t initialize iptables table `nat’: Permission denied (you must be root)
Perhaps iptables or your kernel needs to be upgraded.
ip_forwarding was disabled, but we cannot re-enable it now.
remember to re-enable it manually
How do i fix it? 
And this:
BAC@linux-krz3:~> sudo ettercap -G
root’s password:
ettercap NG-0.7.3 copyright 2001-2004 ALoR & NaGA
GTK+ failed to initialize. Is X running?