The Case of the Vanishing Sata Drives

The Mystery:

I have a Gigabyte GA-X48-DS4 motherboard and I've run into a problem. One or more of the three ST3640323AS drives vanish from Windows Vista Business 64-bit edition. These vanishes are usually characterized by a sudden jump in CPU cycles and system pausing before any program running from that device crashes. This is followed by the corresponding drive disappearing from windows.

Notes:
- System restart does not return drives, they are gone in bios.
- System power off and power on always restores drives.
- Have not been able to get drives to vanish in DOS environment during testing.
- Have tried new SATA cables, swapping power cables, etc.
- Have tried swapping SATA ports.
- Motherboard has been RMAed and returned with no problems.

A Clue:

After looking online it seems that people have had issues with the ICH9R chipset from Intel and Windows Vista 64 bit. I have tried using gigabytes pre-install drivers and their drivers after install and they are supposedly vista compatible.

I've also had a friend run one of the failed drives for several complete writes and wipes with no problems.

So I have to assume its a problem between the Sata Drives, the ICH9R Sata Controller, and the Windows Vista 64x drivers.

Does anyone have any clues or should I just light my desktop on fire?

I've just tried the official ICH9R drivers from Intel during install. Still the same issue, in fact install fails after about 20% when the drive(s) drop out. I am going to check my power supply today, though it seems strange that every other component is working fine.

Had a random thought: are you powering the drives from a PSU with native sata power plugs, or are you using molex to sata adaptors? Bought a small pile of those the other day, & had 2 bad ones out of five or six - and both were intermittents, seemed to drop out when connector was stressed a certain direction, hard to find...