I had a problem in CakePHP (the PHP Framework) where when I wasy tring to do a slightly different setup to the standard.
I had the need to upgrade iptables to 1.4 from the stock in centos5.
My host upgraded the VPS node kernal to only support 1.4 iptable modules. If for example are an unlucky person with the following error:
Testing ipt_owner/xt_owner…FAILED [Error: iptables: Unknown error 18446744073709551615] – Required for SMTP_BLOCK and UID/GID blocking features
Then upgrading might be a fix for you. I though it would be a difficult task. but its not to bad.