Is Diskeeper Automatic Mode safe?

I've got a pair of servers running PostgreSQL 8.0.4 on Windows. We
have several tables that add and delete massive amounts of data in a
single day and are increasingly having a problem with drive
fragmentation and it appears to be giving us a decent performance hit.
This is external fragmentation we are dealing with. We already vacuum
the tables on a regular basis to reduce internal fragmentation as best
as possible.

Currently I shut down the PostgreSQL service every few weeks and
manually run a defragment of the drive, but this is getting tedious.
Diskeeper has an Automatic Mode that runs in the background all the
time to handle this for me. They advertise they are compatible with MS
SQL server, but don't appear to have any specific info on PostgreSQL.

I'm curious if anyone else has used Diskeeper's Automatic Mode in
combination with PostgreSQL to defrag and keep the drive defragged
while PostgreSQL is actually running.

Thanks!

-chris
<www.mythtech.net>