[CentOS] Anyone get the Adaptec-39320A driver to install?

I'm trying to get the RHEL-5 version of their kernel driver to install
with no luck so far.

http://www.adaptec.com/en-US/support/scsi/u320/ASC-39320A-R/

Here is what I'm seeing when I install their provided .RPM:

[root at hcnas ~]# rpm -i a320raid.rhel5.i686.rpm

Adaptec adp94xx driver installer - V1.2.5934.0-1


Backing up all modified files to /boot/adp94xx-backup-4

Using GRUB configuration
If this is not what you want, rename your /boot/grub/grub.conf file
/boot
-rw------- 1 root root 2403318 Jul 27 07:39 initrd-2.6.18-8.el5.img

/boot/vmlinuz-2.6.18-8.el5 /boot/initrd-2.6.18-8.el5.img CentOS
(2.6.18-8.el5)
Configuration [CentOS (2.6.18-8.el5)]
/boot/vmlinuz-2.6.18-8.el5 -> 2.6.18-8.el5

****** PROBLEM *******
No prebuilt module for 2.6.18-8.el5 i686
**********************

***************************************
******** NO MODULES INSTALLED *********
***************************************

Done.
error: %post(a320raid-3.00.063.5.V580A1-1.i686) scriptlet failed, exit
status 1
[root at hcnas ~]#