If you try to set the preferences they are reset and your setting are lost as soon as you close the preference window.
This makes the 'On demand' unreliable.
Only the 'Schedule' can be trusted, as the preferences for each task are separate from the Global preferences. And The Global preferences are what is getting reset.
The base app keeps global prefs in the windows directory, so it can't even save them on vista or 7. They don't work right anyway. You can easily run on demand through the gui.
Or did the previous 8.8.8 release work differently for you?
Sometimes, the impossible can become possible, if you're awesome!