The REDACTED at Dell don't support Centos 5.3 on r610s raid card (Dell H200). I seriously REDRACTED hate propriety drivers and it's going to be a constant nightmare as we change kernel versions, but whatever. The problem is basically that the drivers are signed for Redhat Enterprise and Centos doesn't like that. So you have to crack open the driver package and remove the signing. A fixed package is available here: i686 x86_64.
I robbed most of the instructions to do this from here: