MacPro keeps killing hard drives!

Hi all,

I had a search on here beforehand to see if anyone else has had this issue. I couldn't find a close match, but my apologies if I missed one.

I have an early model Mac Pro (v1.1) and last week the original hard drive (a good 6 years old) suddenly died. It was without any warning as previously the computer had been working fine. The only problem I noticed was immediately before the drive died, Firefox locked up my Mac to the point where I had to do a hard reset. When I turned the Mac back on, it would hang at the Blue screen with a spinning beachball.

I booted from the Snow Leopard install disk and did a HDD repair, where I learnt the drive was dead.

Promptly I bought a brand spanking new WD 1TB HDD, and reinstalled everything. I then tried to use a data recovery app (Disk Driller) to copy what it could off the old HDD, which was running off one of the internal SATA conenctions. This seemed to cause problems again, locking up the computer and so forth, to the point where again I had to reinstall Snow Leopard.

Now, I have the original dead 250gb HDD in an external case, attempting a restore by backing it up as a DMG to the new HDD. AGAIN, this froze over night while it was doing it's thing. Ordinarily I'd give up, but there was 30gb of photos on this drive as well as old work I wanted to keep.

SO: Now it appears my new HDD is dead.

I don't know that I've explained this very well, but here's my question. Is it possible there is something in my MacPro (software -- I'm looking at you Disk Driller!) or otherwise that is killing my HDDs?

The first HDD was getting on, so I can see how that could have died (although, it was suspiciously sudden). However, my new HDD is now only FOUR DAYS OLD and when I run Disk Utility from my install disk, it warns that the HDD has failed and to back up what I can.

Appreciate any help I can get!

Dave