CentOS 5 Hardware :: Hosed Intel DP35DP Centos 5.3 Upgrade?

I have an intel DP35DP motherboard - ICH9 southbridge - set to AHCI mode. Working fine under 5.2. Yesterday I updated to centos 5.3, and got kernel 2.6.18-128.1.16 and now it can't boot. It hangs trying to read sata1 with DRDY errors and exceptions.So then I installed 5.3 from a DVD onto a new drive, and got kernel 2.6.18-128. This worked, most of the time, but occasionally gave me this error. I then updated my BIOS, and the error went away.Then I updated this new working drive to the latest kernel (yum update again) and got kernel 2.6.18-128.1.16, and now it wont boot again, with the same message.

ata1: failed to read log page 10h (errno=-5)
ata1.00 exception Emask 0x1 SAct 0x1 SErr 0x0 action 0x0
ata1.00: irq_stat 0x40000008
ata1.00: cmd 60/08:00:61:4b:38/00:00:3a:00:00/40 tag 0 ncq 4096 in
ata1.00: status: { DRDY }
ata1.00: revalidation failed (errno=-2)
ata1.00: revalidation failed (errno=-2)

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