IpTables does not properly shut down (/etc/init.d/iptables).
Error message during poweroff: "Your Kernel lacks iptables support, please load\nappropriate modules and try again.". The problem is apparent in edge, but not in 3.18.
The reason is a test for /proc/net/ip_tables_names in /etc/init.d/iptables; ip_tables_names is missing. Iptables seems to work perfectly, as shown in "iptables -L -n -v". Yet, the /proc file is never created. In /etc/init.d/iptables, ip_tables_names is not used for anything else except the existance check.