I got Diskeeper 2008 Pro Premier a while back hoping to keep my laptop
in good shape. Then I performed a system update which included the
update of some Intel drivers for disk management and wireless network
management. As a result my laptop started freezing a while after going
into screen saver mode. I spent a few days on the phone with IBM/
Lenovo support and Microsoft support to resolve this issue. They could
not solve it, but I stumbled onto the solution when I noticed that the
hard drive was very active after going into the screen saved mode,
which made me realize that the automatic defragmentation of Diskeeper
was kicking in. When I disabled that automatic defragmentation the
problem was gone. I then uninstalled and reinstalled Diskeeper at
Diskeeper's direction which resolved the issue entirely. Diskeeper
still won' admit that there is an issue between Vista driver updates
and Diskeeper, but I know what happened to me. It took me a few days
of wasted time, so I figured I would post my experiences.

There is an option in Diskeeper's settings which says that the automatic defragmentation will kick in when the system is idle. It might have been the default option even. My advice is if you want to defragment your hdd with Diskeeper, turn the automatic defragmentation off.