2x SE16 HD failure

Last night my wife turned on the computer to be greeted with “no boot device, insert and press any key” or similar.

Upon inspection it would seem that TWO Western Digital WD2500KS hard drives have failed. The computer was working fine a couple of hours before.
Both other HD’s are working fine.

The computer is: 
Asus P5B Deluxe MB
Intel E6400 (2.13 C2D) running at 2.8GHZ
Radeon 1950 256mb
2x1GB Geil 4-4-4-12
Maxtor 120gB HD IDE
450+ Watt PSU
DVD/CD Writer Drive
Artic Freezer 7 CPU

I have had a couple of problems with these drives before, where they have refused to work upon boot. Normally after swapping the SATA leads round seem to work. It’s happened three times in the last 2 years, the most recent being 4 days ago. I have never come up with a awnser as to why this happens.

I am wondering ewhat would cause 2 drives to fail? Apart from a power surge (that didn’t seem to affect anything else), I have no idea!

12v is 11.8v
5v is 5.12v using a multimeter.

I’ve posted this on another forum, but really wanted more specific advice.

Not likely to have on 2 drives at the same time unless there is a problem coming from the computer.  You should try to test a different hard drive model from WD to see if the problem continues.

All other HD’s work.

I bought a new Caviar Green 1gB to replace them, that works fine.

The problem is the data on the old drives!