Just thought I'd post this in case it helps someone.
I recently started to get this error on boot up. This takes quite a while to stop trying and proceed to boot.
So a little troubleshooting was in order.

1. Not a kernel problem as I re-installed an older version using synaptic and accessed that kernel from the grub menu. Note: the reason for even suspecting the kernel is the problem appeared shortly after doing a yum update which included a new kernel.

2. Not a Redhat problem as Suse and live cds popped the same error.

3. Turned off dma with the command: hdparm -d0 /dev/hda That had no effect on the problem.

4. Not the hard drive as I temporarily replaced the drive.

5. Replaced the IDE cable and BINGO! no more error. I put the suspect cable back in just to be sure and the error came with it. Must have been a loose or broken wire but I sure couldn't see where. Also, I don't know if this has any bearing but it was one of those round ide cables.

After things were humming along again, I turned the dma back on with the command:
hdparm -d1 /dev/hda and set grub to use the latest kernel.