Is this luck or bad luck?

I finally built my new server (that is also the reason that RightHand webs were down this week). It is an Athlon 64 3000, 2Gb RAM, and 3x250Gb disks in RAID 5 configuration + system disk. Since my production computer had a relatively small disk (80Gb) and buying a disk smaller than 250Gb is not optimal, I've decided to buy a 250Gb disk, copy image of my production disk on it and use my production disk for server's system disk. The only problem I foresaw was that I need an application to copy image of my disk to the new one (I really wasn't in mood of reinstalling though reinstalling once in a while is not a bad thing). I decided not to buy Norton's Ghost since it wouldn't be reasonably for one use. Instead I used Ultimate Boot CD which did the job perfectly. So, I've put my old good disk into the server as system disk. I installed fresh new Windows 2003 x64 and everything worked well. Until I restarted server next day. It wouldn't boot anymore - it went into the endless loop of booting/reseting/booting.. Blue screen was saying "UNMOUNTABLE_BOOT_DEVICE". How could that be since it was booting from the same device? It turned out that the my old good disk was failing more and more and finally died on the same day.

Now, the question is: Is this luck (I copied image of it on the new disk just the day before death) or is this bad luck (disk died just the day after I moved it)?