I acquired DG through the recent MU bundle & yesterday I thought I would try out the defrag on my (early model) Intel MacBook Pro.

Big mistake.

Despite an apparently successful defrag, DG left my internal HD in a corrupted state & it refused to boot or let me access any files from it. I had to erase the drive and restore from SuperDuper - luckily I had the foresight to backup beforehand and lost very little data.

It appears that the developers are well aware of the flakiness of their defragging code - given the dire warning they flash before you start the defrag. Needless to say I did not experience any power loss or interruption during the defrag and DG did not report any errors.

My drive was working fine beforehand, with no errors and a fairly recent install of Leopard.

That there exists so many reports of HDs being trashed should make anyone very wary indeed of using the defrag option at least. Although TBH I doubt very much I will try any more of DG's features - given the many hours it has lost me already.