Is I/O access not allways transparent in Windows?

[CruNcher]

Hmm when i use Contig.exe by Mark Russinovich i only see Kernel activity with his own Process Explorer but no I/O access happening tough the Hard Drive is definitely working, how can this be is Low Level Hardware access generally hidden from being traced by the I/O counter in Windows (Defrag API)?

http://s2.directupload.net/images/080421/uh7jgelj.png