Pressing shutdown results in reboot followed by RAID error

[The Boy]

Hi,

I just bought myself a new computer, specs are on my profile, everything works fine, almost...
I'm using Windows Vista Ultimate 32 bit and I have 2xWD6400AAKS (2x640GB) in a RAID 0 array, I have no other hard drives in the machine and I have a SATA DVD-RW drive. Nothing is overclocked.
Everything goes a bit strange when I shut down. Shut down sequence appears to go fine, then it proceeds to restart, then I get a RAID error. When I press F10 to take a look the array only has one of my drives listed and if I select to create a new array the other drive is listed, but only its SATA port number, not it's name or size or anything. Then I turn it off by ctrl+alt+deleting and pressing the power button during POST. If I keep pressing ctrl+alt+del/pushing the restart button I keep getting the same RAID error. The next problem is turning it back on: it turns off after a split second, I have to turn it off at the PSU, wait a bit, then turn it on, it then reports the RAID array as healthy and I can boot windows and continue as usual and everything is stable, I get no read errors/access violations etc. I look in the nvidia control panel and that also reports both drives as healthy.
Also during boot up I hear a high pitched whirring, sort of a "tweeeeeeet...tweeeeeeet...tweeeeeeeet", but only if I'm restarting after the computer's been on and I'm also beginning to think that moving large chunks of data about might cause it to happen.
The puzzling thing is when I press restart in windows instead of shutdown everything works fine. Of course that could just have been a coincidence as this thing has only happened 3 times, however I've had to restart it quite a bit when installing windows and drivers. Also when I tried demonstrating this to my house mate and turned it off after about a minute of being on it shut down fine so it could be related to heat build up. It also means testing out potential solutions could take a long time.

I plan on installing Windows XP and ubuntu at some point and triple booting them, so I'll then be able to see if it's a vista/windows related problem.

Any help would be greatly appreciated.

Chris

EDIT: I had to put the 120mm fan that comes installed in front of the hard drive cage due to the size of my PSU and put it somewhere else so it's no longer pulling air across the hard drives. Anybody think heat could be the cause of all this?

EDIT: It seems to be a problem with one of the hard drives, I turned RAID off and turns out it couldn't detect one of the drives. Could be because one of the cables was a bit stretched. Letting it cool down seems to fix it.

EDIT: Problem solved, one of the hard drives is faulty.