Hey Froggie,
We've made a little headway in my support ticket regarding this issue. They made a special build that fixed the defragging problem on my machine and you're welcome to give it a try (I asked).
rollback-test0621.zip
Obviously, you try this at your own risk.
As for why this is happening, I don't really know. Honestly, I remember reading that this feature was supposed to run whenever it detected your computer was idle, not based on a specific time interval... so I guess I wouldn't have expected them to describe it as an "hourly" process.
However, I do remember reading something about the /disableOPT functionality being offered more readily (in the next version?). I wouldn't be surprised if there was a new check box in the program options.
On an aside, have you had a chance to experienced any problems booting up after Hibernation, Froggie..? I'm still plagued with "Windows did not shut down properly" when using Rollback Rx. I'm wondering if it warrants its own thread, considering there's a temporary fix for the defrag issue.
Oh, btw, lemme know how that version works, if you try it!