diskeeper is one of the better defraggers and has been in the biz for 20+ years. xp's built-in defragger is based on an early version of diskeeper and they make versions for servers also. so diskeeper is a good product.

did you allow diskeeper to finish completely (no powering off in the middle)? diskeeper won't attempt a defrag if it detects file system corruption, but it can provoke corruption if certain key areas of your disk/fat are flaky.

i'd contact diskeeper before you do anything.