iptables v1.3.5: can't initialize iptables table `nat': Table does not exist (do you need to insmod?)
This solution applies to all other iptables modules/problems for OpenVZ, you'll just need to add them to both lists/lines below if you have modules other than what I have below.
The modules need to be enabled in both iptables and the OpenVZ hostnode itself and then the containers which need it must be restarted.
How To Enable IPTables Modules in OpenVZ........
The default options for iptables are very basic. Here is what you need to do in order to enable them in OpenVZ.
1.) Add the modules to iptables and restart iptables:
Edit the line as so:
IPTABLES_MODULES="ipt_REJECT ipt_tos ipt_TOS ipt_LOG ip_conntrack ipt_limit ipt_multiport iptable_filter iptable_mangle ipt_TCPMSS ipt_tcpmss ipt_ttl ipt_length ipt_state iptable_nat ip_nat_ftp"