That is a strange problem, and I would have to look at the power supply if you had 3 drives fail within a relatively short amount of time. I know that someone already recommended that to you, but unless you have extraordinarily bad luck, that is really the only common denominator that would effect 3 different hard drives if I'm reading your post correctly. Occasionally we see drives that have heads which have degraded in functionality or damaged pre-amps due to voltage irregularities. Most of these cases were traced back to power supply problems.
Edited by ACS Data Recovery, 16 September 2008 - 02:45 PM.