There is an inherent problem with Diskeeper and open file backup programs
such as the one from veritas. If both are running at the same time, file
corruption will occur. (this information is posted on the Diskeeper site)
Unfortunatley we experienced this problem first hand with NT 4.0 - Backup
Exec 7.3 - OFO and the actual Diskeeper product.

With the addition of an integrated defragmentation utility with W2K (that
uses the Diskeeper product), we are feeling somewhat cautious of loading 8.6
and the OFO option. Has anyone had experiences, good or bad,with
defragmenation in W2K and OFO.