I use Diskeeper 2008 Pro, and it's been flawless so far. I am running the trial version of Diskeeper 2009 Pro on the second system, and it seems to be better than 2008. Merely an unscientific observation, but the defrag seems to be 'faster' now. Another nice addition is the file placement feature now in the Pro version.
Both are 32-bit XP systems BTW.
Both are 32-bit XP systems BTW.