kernel: journal commit I/O error

[Daran]

I've done extensive (debatable) Internet searches on this error. My description follows many others I've seen:

open terminal windows shows "kernel: journal commit I/O error"
file system set to RO
reboot clears the problem

I'll add one more symptom: low pitch hum from the HD for about 10 seconds just before it happens.

HDD: Seagate Barracuda 300Gb SATA
OS: Fedora Core 5, clean install from CDs, yum update all pkgs

I have run the Seagate full diagnostic scan from bootable CD. It found a single bad sector.

I need advise on how to diagnose or isolate the problem. I believe the problem will be:

1 - HDD defective
2 - SATA controller defective
3 - sata_driver error

Can you shed some light on the next steps?

thanks for any advice,