All drives are doing it, but it seems that the WD green ones are being affected more than the old seagate 500gig.
Have tried jumering drives to 150 meg mode incase its my cheap 90cm UV reactive SATA cables doing something dodgey between the mobo and the otehr case with all the drives in it.
Tried a new PSU for the drives, and also tried it on the computer. No change either way.
Am running AHCI mode if it matters. Anyone seen anything similar? Im going to get a PCI card and try that soon and see if it helps.