CentOS 5 Networking :: Proxy - Error "can't Initialize Iptables Table `nat': Table Does Not Exist"

We purchased a virtual server from GoDaddy (1 month trial) to set up as a proxy for our networks (24 of them). I am having 2 separate issues. The first is I can't configure/install NAT and support is telling me the only way I can is to purchase a dedicated server. Here's the error:

iptables -t nat -A PREROUTING -p tcp --dport 80 -j REDIRECT --to-port 3128 iptables v1.3.5: can't initialize iptables table `nat': Table does not exist (do you need to insmod?) Perhaps iptables or your kernel needs to be upgraded. Here's the fix: [URL] So, what I am hoping to do is configure this by just opening port 3128 directly, and only allowing access from our networks. As a test I did this and allowed only from our office and it did not work. However I can't connect, so I am wondering what I am doing wrong? Here's my squid configuration:

[Code]....